HIGHLIGHTS

Zone 1 gold mineralization now extends below 700 meters and remains open at depth.
Zone 1 mineralisation extends directly from surface.
2.34 g/t Au over 9.34 metres intersected in Zone 2 as the Company advances geological interpretation and plans next phase of drilling.
The zone 1 eastern shoot, outlined by Hole NO-26-21a (4.92 g/t gold over 11.37 metres) located approximately 200 metres below NO-26-07 (8.22 g/t gold over 8.5 metres), will be a major focus of our next drill program.

MONTREAL, Sept. 16, 2026 (GLOBE NEWSWIRE) -- Opus One Gold Corp. (TSX-V: OOR) (the “Company” or “Opus One”) is pleased to announce the final assay results from its 2026 drilling program on its 100%-owned Noyell Gold Property, located in the northern portion of the Abitibi Greenstone Belt near Matagami, Quebec.

Those final results are completing a successful 2026 drilling campaign that significantly advanced the Company’s understanding of the Noyell property gold system. Released drill holes true width values were calculated using Geotic Log software.

Most importantly, drilling has now traced the Zone 1 gold-mineralized structure continuously from surface down to approximately 750 metres vertical depth, where it remains open at depth.

The 2026 program also identified a strong mineralized vector in the eastern portion of Zone 1, highlighted by previously announced hole NO-26-21a, which returned 4.92 g/t Au over 11.37 metres (9.08 metres true width) at approximately 700 metres vertical depth (June 17h, 2026 press release)

In addition, Opus One's first drilling program, approximately 3 kilometres west of Zone 1 at the West boundary of Noyell property, successfully intersected gold mineralization in all five holes drilled across approximately 800 metres of strike at the newly explored Zone West, providing the Company with a second priority area for follow-up drilling.

2026 NOYELL PROGRAM HIGHLIGHTS

Zone 1 has now been traced continuously from surface to approximately 750 metres vertical depth and remains open at depth.
Previously reported hole NO-26-21a returned 4.92 g/t Au over 11.37 metres, (June 17^th, 2026, press release) including a true width of 9.08 metres, representing the deepest significant Zone 1 intersection drilled by Opus One to date.
Previously reported hole NO-26-07 returned 8.22 g/t Au over 8.5 metres (7.16 metres true width) (May 7^th, 2026, press release), including 49.1 g/t Au over 1.34 metres.
Hole NO-26-18 returned 2.34 g/t Au over 9.34 metres in Zone 2, an unusually broad mineralized intersection for Zone 2 that warrants additional geological evaluation.
The eastern portion of Zone 1 has emerged as the principal vector for potential depth extension, particularly below NO-26-21a.
First-pass drilling at Zone West, approximately 3 kilometres west of Zone 1, intersected gold mineralization. All five holes drilled across approximately 800 metres of strike intersected gold mineralization.
Zone West remains sparsely drilled and has not yet been tested below 300 metres vertical depth.
Geological compilation and reinterpretation of both Zone 1 and Zone West are underway to establish priorities for the next phase of drilling.

FINAL ZONE 1 RESULTS FOR 2026

Opus One has now received assay results from the final five drill holes completed at Zone 1 during the 2026 program. (Tables 1 and 2)

Hole NO-26-08 was designed to test the potential western extension of Zone 1 at approximately 300 metres vertical depth. Both Zones 1 and 2 returned marginal gold values, consistent with the Company's geological interpretation that the western portion of Zone 1 weakens in this area until further drilling is performed in this area.

Hole NO-26-18 was drilled to test an interpreted west-dipping mineralized trend associated with Zone 1. Zone 1 returned marginal gold values, suggesting that the interpreted trend may not continue in this area, as originally anticipated.

However, Zone 2 produced an unexpected and potentially significant intersection of 2.34 g/t Au over 9.34 metres.

The width and grade of this intersection are noteworthy for Zone 2, which has generally returned narrower and lower-grade intersections. The Company intends to incorporate this result into its ongoing geological interpretation to determine whether it represents a locally developed mineralized shoot or a potentially more significant target.

The remaining holes, NO-26-14a, NO-26-19 and NO-26-23b, were designed primarily to test the vertical continuation of Zone 1.

All three holes intersected Zone 1 at the anticipated geological position.

Combined with the Company's previously reported results, these holes have helped refine the interpretation of the mineralized system and indicate that the strongest vector for continued depth exploration is located in the eastern portion of Zone 1, around and below hole NO-26-21a.

ZONE 1 – A GOLD SYSTEM OPEN AT DEPTH

The 2026 program represents an important step forward in defining the geometry and scale of Zone 1.

Following the Company's 2025 drilling campaign, Zone 1 was identified from surface to approximately 500 metres vertical depth.

The 2026 program has now extended the known mineralized structure to approximately 750 metres vertical depth, while confirming significant gold grades and widths along the principal eastern mineralized shoot.

Among the key previously reported 2026 intersections are:

NO-26-07:
8.22 g/t Au over 8.5 metres (May 7^th, 2026, press release)
(true width: 7.16 metres), including intersection of 49.1 g/t Au over 1.34 metres

NO-26-21a:
4.92 g/t Au over 11.37 metres (June 17^th,2026, press release)
(true width: 9.08 metres)

NO-26-21a was drilled approximately 200 metres vertically below NO-26-07 on the same cross-section, providing an important indication of the vertical continuity of the high-grade eastern mineralized shoot.

Importantly, the Zone 1 mineralized structure remains open at depth.

The area below NO-26-21a will therefore represent a priority target as Opus One develops its next drilling program.

A SECOND EXPLORATION FRONT AT ZONE WEST

The 2026 program also marked Opus One's first drilling of the western portion of the Noyell Property, approximately 3 kilometres west of Zone 1.

Five exploratory holes totalling 1,467 metres were completed over approximately 800 metres of strike.

Every hole intersected the targeted geological structure and returned significant gold values above 300 metres vertical depth.

Previously announced results included (September 2^nd, 2026, press release)

1.03 g/t Au over 8.90 metres in NO-26-09;
3.48 g/t Au over 1.19 metres in a second mineralized zone in NO-26-09;
0.50 g/t Au over 10.41 metres in NO-26-16;
1.11 g/t Au over 3.96 metres in NO-26-17;
1.34 g/t Au over 8.29 metres in NO-26-20; and
1.18 g/t Au over 9.07 metres in NO-26-22.

The new Zone West geological environment differs materially from Zone 1 and includes alternating sheared sedimentary and volcanic rocks.

The mineralization occurs within a broader altered and sulphide-bearing structural package and remains sparsely tested.

With gold mineralization now identified over approximately 800 metres of strike and no drilling yet completed below approximately 300 metres vertical depth, Opus One considers Zone West an important target for future definition and exploration drilling.

NEXT STEPS

With all 2026 assay results now received, the Company's geological team is integrating the complete drill database into an updated geological and structural interpretation of the Noyell Property.

The work will focus particularly on:

defining the continuation of the high-grade eastern shoot of Zone 1 below NO-26-21a;
evaluating the significance and continuity of the broad Zone 2 intersection in NO-26-18;
refining the geometry of Zone 1 between surface and approximately 750 metres vertical depth; and
developing follow-up drill targets across the approximately 800-metre mineralized trend identified at Zone West.

The resulting interpretation will be used to establish priorities for the Company's next phase of drilling.

CEO COMMENT

Louis Morin, President and CEO of Opus One Gold, commented:

"The 2026 program has materially advanced our understanding of Noyell. A year ago, our drilling had identified Zone 1 to approximately 500 metres vertical depth. We have now followed the mineralized structure from surface, down to approximately 750 metres, and most importantly, it remains open at depth.

The most important development for Zone 1 is that we believe we have identified the principal vector to be followed deeper. Hole NO-26-21a returned 4.92 g/t gold over 11.37 metres at approximately 700 metres vertical depth, approximately 200 metres below NO-26-07, which returned 8.22 g/t gold over 8.5 metres. This eastern shoot will be a major focus of our next phase of drilling.

At the same time, our first drilling program at our new Zone West has given us another area to advance. Every drill hole intersected gold mineralization across approximately 800 metres of strike, and the system has only been tested at shallow depths. We now have two distinct areas identified at Noyell, where additional drilling can potentially expand the mineralized footprint.

Our geological team is integrating all the 2026 results into an updated model. The objective is straightforward: follow the strongest portion of Zone 1 deeper while beginning to systematically define the scale and potential of Zone West."

LAST DRILL HOLE COORDINATES (Table 1)

LAST DRILL HOLE COORDINATES (Table 1)

LAST ASSAY RESULTS (Table 2)

LAST ASSAY RESULTS (Table 2)

DRILL HOLE LOCATION MAP – ZONE 1

DRILL HOLE LOCATION MAP – ZONE 1

LONGITUDINAL SECTION – ZONE 1

LONGITUDINAL SECTION – ZONE 1

Sample preparation, analysis and QAQC program

All core recovered is NQ size. All samples are described, labelled, cut (diamond saw) and bagged at Technominex’ facilities in Rouyn-Noranda. Samples are then shipped to AGAT certified Laboratory in Val D’or for preparation and analysis. Samples are assayed for gold using Fire Assay - Trace Au, ICP-OES finish (50g charge). All samples equal or above 10 g/t Au are submitted to ore grade gravimetric finish. Multi element analysis is performed using Aqua Regia Digest - Metals Package, ICP-OES finish.

Opus One’s QAQC program consists of one control sample inserted, at Technominex’ facility, after 9 regular samples. Control samples consist of a certified blank and various gold grades certified material.

OPUS ONE GOLD CORPORATION INC.

Opus One Gold Corporation Inc. is a mining exploration company focused on discovering high-quality gold and base metals deposits within strategically located properties in proven mining camps, close to existing mines in the Abitibi Greenstone Belt, north-western Quebec and north-eastern Ontario - one of the most prolific gold mining areas in the world. Opus One holds assets in the Val-d'Or and Matagami mineral districts.

An independent qualified person, Pierre O’Dowd P.Geo, has verified and approved the data disclosed, including sampling, analytical, and test data underlying the information or opinions contained in the written disclosure as required by section 3.1 and 3.2 of NI43-101.

Forward-Looking Statements

This news release contains statements that may constitute “forward-looking information” within the meaning of applicable Canadian securities legislation. Forward-looking information may include, among others, statements regarding the future plans, costs, objectives or performance of Opus One, or the assumptions underlying any of the foregoing. In this news release, words such as “may”, “would”, “could”, “will”, “likely”, “believe”, “expect”, “anticipate”, “intend”, “plan”, “estimate” and similar words and the negative form thereof are used to identify forward-looking statements. Forward-looking statements should not be read as guarantees of future performance or results, and will not necessarily be accurate indications of whether, or the times at or by which, such future performance will be achieved. No assurance can be given that any events anticipated by the forward-looking information will transpire or occur, including the anticipated exploration program on the project, the results of such exploration program, the development of the project and what benefits Opus One will derive from the project, the expected demand for lithium. Forward-looking information is based on information available at the time and/or management’s good-faith belief with respect to future events and are subject to known or unknown risks, uncertainties, assumptions, and other unpredictable factors, many of which are beyond Opus One’ control.

These risks, uncertainties and assumptions include, but are not limited to, those described under “Financial Instruments” and “Risk and Uncertainties in Opus One’ Annual Report for the fiscal year ended August 31^st, 2025, a copy of which is available on SEDAR at www.sedar.com and could cause actual events or results to differ materially from those projected in any forward-looking statements. Opus One does not intend, nor does Opus One undertake any obligation, to update or revise any forward-looking information contained in this news release to reflect subsequent information, events or circumstances or otherwise, except if required by applicable laws.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of the release.

For more information, please contact:

Louis Morin

Chief Executive Officer & Director

Tel.: (514) 591-3988

Michael W. Kinley, CPA, CA

President, Chief Financial Officer & Director

Tel: (902) 402-0388

info@OpusOneGold.com

Visit Opus One’s website: www.OpusOneGold.com

OPUS ONE’S NOYELL PROPERTY LOCATION MAPS

OPUS ONE’S NOYELL PROPERTY LOCATION MAPS

Opus One Gold Completes 2026 Drill Program at Noyell, Extending Zone 1 Gold Mineralization From Surface to Approximately 750 Metres and Remaining Open at Depth