Pace Performance's Josh McLean claimed his fourth reverse grid win of the year with a controlled drive in the Donington Park finale.
The British driver made a good start from pole position, but it was Douglas Motorsport’s Conor Grant who was the big mover as he shot from fourth to second on the first lap.
The race was neutralised almost immediately though, with the Fox Motorsport car of Archie Bullard dropping fluid on the opening lap and coming to a halt at Coppice.
Racing resumed at the end of lap four with nine and a half minutes remaining. The top-seven remained static, though behind, race two winner Stevenheydens was on the move, passing Thomas Ingram Hill and Franek Cegielski on consecutive laps to move into seventh, having started ninth.
The safety car was deployed again on lap six though, after Jasser Iskander spun into retirement on the start/finish straight after colliding with countryman Faris Organji, while the Pace Performance car of Torrin Byrne dropped out of sixth place on the approach to McLeans.
With very little time remaining, the race finished under safety car, with McLean taking victory ahead of Grant, while the second Pace Performance entrant of John O'Donnell claimed a maiden podium in third.
Douglas Motorsport's Dayton Coulthard was classified fourth ahead of Hillspeed's Connor Willis, with Stevenheydens sixth.
Cegielski and Ingram Hill settled for seventh and eighth, with championship protagonists Fred Green and Alex O'Grady completing the top-10 after a mid-race battle.
O'Grady leaves Donington Park with a 49-point lead at the top of the standings. With 102 available at the Brands Hatch finale, no fewer than five drivers remain in mathematical contention for this year's title.
GB4 Championship, partnered by the BRDC, Donington Park, provisional race three result:
1. Josh McLean, Pace Performance, 9 laps
2. Conor Grant, Douglas Motorsport, +2.083s
3. John O'Donnell, Pace Performance, +2.633s
4. Dayton Coulthard, Douglas Motorsport, +3.866s
5. Connor Willis, Hillspeed, +4.981s
6. Yani Stevenheydens, Elite Motorsport, +5.234s
7. Franciszek Cegielski, Fortec Motorsports, +6.360s
8. Thomas Ingram Hill, Fortec Motorsports, +6.835s
9. Fred Green, Elite Motorsport, +8.553s
10. Alex O'Grady, KMR Sport, +9.157s
11. Matan Achituv, Elite Motorsport, +9.596s
12. Enzo Hallman, Hillspeed, +11.318s
13. Demitri Nolan, Hillspeed, +12.469s
14. Archie Davies, Scorpio Motorsport, +13.497s
15. Michael Koh, Arden Motorsport, +14.262s
16. Romuald Bocquet, Scorpio Motorsport, +15.339s
17. Jordyn Martin, Fortec Motorsports, +15.964s
18. Jamie Leverton, Nitrous Competitions ADM Racing, +17.322s
19. Lily-May Watkins, KMR Sport, +17.956s
20. Solenn Amrouche, Arden Motorsport, +18.388s
21. Enzo Rujugiro, Fox Motorsport, +19.749s
22. Caitlyn McDaniel, Nitrous Competitions ADM Racing, +20.482s
23. Holly Miall, KMR Sport, +21.229s
24. Yana Kapoor, Arden Motorsport, +22.953s
DNF. Faris Organji, Scorpio Motorsport, 6 laps
DNF. Torrin Byrne, Pace Performance, 5 laps
DNF. Jasser Iskander, Fox Motorsport, 5 laps
DNF. Archie Bullard, Fox Motorsport, 0 laps