Nitrous Competitions ADM Racing's Luke Hilton topped the times on day one of official pre-season testing at Snetterton, with the very last lap of the day. 

The British driver, set for his second GB4 campaign, started his last lap with just seconds remaining on the clock, and posted a 1m40.093s, enough to squeeze ahead of Elite's Fred Green, who had been quickest until that point. 

Hilton was already on course to top the times for the session, until his final tour proved enough to lead the day overall.

Having topped two of the day's four sessions, Ginetta Junior graduate Green had to settle for second, just under a tenth of a second away from Hilton's outright best time, with KMR Sport's Alex O'Grady next up and only 0.023s further back.

Dayton Coulthard put his Douglas Motorsport car fourth overall, 0.026s away from O'Grady and 0.041s ahead of the second Elite car of Matan Achituv. 

Hillspeed's Connor Willis was another late improver to set the sixth fastest time, and less than two tenths further back. 

Coulthard's teammate Jason Smyth was next up as he moves up from Formula Ford, while Fortec returnee Thomas Ingram Hill was fastest in the first session of the day, enough to put the young Brit eighth overall. 

The second Hillspeed car of Enzo Hallman, who is evaluating a series return, and Ingram Hill's teammate Franek Cegielski, completed the top-10, which was covered by 0.882s.

A total of 28 cars were in action at Snetterton, as GB4 gears up for its biggest grid yet. Fox Motorsport handed a test to Archie Bullard, while Arden trialled Michael Koh and Charlie Myers. Alex Liu meanwhile circulated in a fourth Elite Motorsport car. 

Testing at Snetterton resumes tomorrow with four further sessions. 

GB4 Championship, partnered by the BRDC, Snetterton test day one result:
1. Luke Hilton, Nitrous Competitions ADM Racing, 1m49.093s
2. Fred Green, Elite Motorsport, +0.096s
3. Alex O'Grady, KMR Sport, +0.119s
4. Dayton Coulthard, Douglas Motorsport, +0.145s
5. Matan Achituv, Elite Motorsport, +0.186s
6. Connor Willis, Hillspeed, +0.357s
7. Jason Smyth, Douglas Motorsport, +0.444s
8. Thomas Ingram Hill, Fortec Motorsport, +0.472s
9. Enzo Hallman, Hillspeed, +0.570s
10. Franek Cegielski, Fortec Motorsport, +0.882s

Click here for full result.