KMR Sport's title challenger Alex O'Grady topped the times in the first of four test sessions to be held at Donington Park today (Thursday).
The Irishman posted a 1m29.769 right at the end of the half hour session, enough to put him just over a tenth of a second clear of Elite's championship leader Fred Green.
Fortec's Thomas Ingram Hill was just 0.068s behind in third, with the top-three covered by less than two tenths.
Pace Perfomance's Torrin Byrne was next up in fourth, just ahead of Ingram Hill's teammate Franciszek Cegielski, with Douglas Motorsport's Dayton Coulthard completing the top-six, which was covered by less than half a second.
Hillspeed's Enzo Hallman and Nitrous Competitions ADM Racing's Luke Hilton were seventh and eighth ahead of the second Hillspeed and Elite cars of Connor Willis and Matan Achituv respectively. The top-10 was split by 0.778s, with the top-12 covered by less than a second.
Session two is due to commence at 11.30.
GB4 Championship, partnered by the BRDC, Donington Park Thursday test session one result:
1. Alex O'Grady, KMR Sport, 1m29.769s
2. Fred Green, Elite Motorsport, +0.116s
3. Thomas Ingram Hill, Fortec Motorsports, +0.184s
4. Torrin Byrne, Pace Performance, +0.380s
5. Franciszek Cegielski, Fortec Motorsports, +0.416s
6. Dayton Coulthard, Douglas Motorsport, +0.489s
7. Enzo Hallman, Hillspeed, +0.548s
8. Luke Hilton, Nitrous Competitions ADM Racing, +0.570s
9. Connor Willis, Hillspeed, +0.763s
10. Matan Achituv, Elite Motorsport, +0.778s
Click here for full result.