Rodin Motorsport's Alex Ninovic survived a 10 second jump start penalty to win the second race of the weekend at Donington Park.
The championship leader started from second on the grid but made his launch too early to get past pole sitter Reza Seewooruthun (Argenti with Prema), thereby collecting the penalty.
But the Australian driver entered time trial mode to extend his advantage over Seewooruthun to over ten seconds, thus retaining his lead when the penalty was applied.
Hitech TGR's Deagen Fairclough chased down Seewooruthun for second spot, but had to settle for third ahead of Xcel Motorsport's Patrick Heuzenroeder, who, after making some overtakes on track, still just about remains in mathematical contention for the title.
Also in the battle for fourth in the early stages was Hillspeed's Lucas Fluxa who finished fifth, followed by Patricio Gonzalez of VRD, who secured his best finish of the season so far in sixth.
Keanu Al Azhari (Hitech TGR), also in the battling pack, claimed seventh just over half a second back from Gonzalez, ahead of Xcel Motorsport's Jack Sherwood in eighth.
Ninth went to Racelab's Max Taylor, and Rodin's Gianmarco Pradel completed the top ten finishers, now out of title contention.
Ninovic is able to claim the title in this afternoon's race at 16:22 if he outscores Heuzenroeder by three points.
GB3 Championship, partnered by the BRDC, Donington Park race two provisional result:
1. Alex Ninovic, Rodin Motorsport
2. Reza Seewooruthun, Argenti with Prema, +1.131s
3. Deagen Fairclough, Hitech TGR, +1.504s
4. Patrick Heuzenroeder, Xcel Motorsport, +3.828s
5. Lucas Fluxa, Hillspeed, +7.943s
6. Patricio Gonzalez, VRD, +9.531s
7. Keanu Al Azhari, Hitech TGR, +10.195s
8. Jack Sherwood, Xcel Motrosport, +13.796s
9. Max Taylor, Racelab, +15.778s
10. Gianmarco Pradel, Rodin Motorsport, +16.055s
11. Enzo Tarnvanichkul, VRD, +16.316s
12. Abbi Pulling, Rodin Motorsport, +16.943s
13. Liam McNeilly, Fortec Motorsport, +18.978s
14. Kabir Anurag, Xcel Motorsport, +20.430s
15. Bart Harrison, JHR Developments, +22.682s
16. Rodrigo Gonzalez, VRD, +24.305s
17. Flynn Jackes, Elite Motorsport, +33.212s
18. Bianca Bustamante, Elite Motorsport, +38.300s
DNF. Kai Daryanani, JHR Developments