Dan Kneen scythed his way through from fourth place on the opening lap of the feature Tandragee 100 Superbike race to clinch a stunning victory on the Tyco BMW on Saturday.
A sizzling race, held in the warm sunshine in County Armagh, saw pole man Derek Sheils streak into an early lead on the Cookstown/B.E. Racing Suzuki.
Sheils was pursued by Derek McGee, Michael Sweeney and Kneen as the leading quartet broke clear of newcomer Davey Todd and William Dunlop.
Dubliner Sheils held the advantage until McGee took up the running on lap four, with Kneen now up to third ahead of Sweeney.
Kneen gained another place as he edged past Sheils into second place on the penultimate lap and he managed his race to perfection, surging into the lead on the final lap.
McGee tried all he could to hit back on his Kawasaki ZX-10R but Kneen prevailed in a thriller to win by 0.4 seconds, with Sheils rounding out the podium. The top three were covered by half-a-second as the feature race lived up to its billing.
Dunlop and Todd crashed out unhurt at Bells crossroads after a coming together, with Adam McLean picking up the pieces on the McAdoo Kawasaki to move into fifth place, which he held until the finish. Thomas Maxwell completed the top six.
After winning the Supersport 600 race, McGee made it a double on the day as he won the Supertwins race on the KMR Kawasaki from Adam McLean (Roy Hanna Kawasaki).
Todd had been holding a safe third place when he was forced out with a machine problem.
The Moto3/125GP race went to Paul Robinson on the CB Racing Honda from Joe Loughlin, who was the first 125cc rider over the line ahead of Nigel Moore.
Daryl Tweed won the concurrently-run Lightweight Supersport race on his 400cc Kawasaki.
Michael Browne won the Senior Support race by almost 28 seconds from Wayne Sheehan, while the Junior Support race - postponed from earlier in the day - went to Wayne Sheehan by 0.8 seconds from his brother Barry.