Hillspeed's Freddie Slater set the pace in official GB3 Championship testing on the Brands Hatch Grand Prix Circuit on Tuesday.
The British driver, fresh from his FIA F3 podium finish in Bahrain last weekend, saved his best until the final session, recording a 1m19.633s to become the fourth different driver to head a session during the day.
Ninovic was just a tenth of a second further back, courtesy of his session three topping effort, with lap times considerably quicker in the afternoon than during the morning sessions, which were affected by rain. All but four drivers recorded their best laps in the final session of the day.
The lead duo were a quarter of a second clear of the field, with Rodin's Gianmarco Pradel third quickest and a tenth ahead of Hitech's Deagen Fairclough, who had topped session one.
James Higgins, who continues to evaluate a drive in the series with Fortec, was fifth quickest, a quarter of a second ahead of Argenti with Prema's Reza Seewooruthun, another contender to lead a session with his effort in the second test.
JHR Developments' Kai Daryanani was next up in seventh, 0.039s clear of Xcel Motorsport's Patrick Heuzenroeder, with Elite Motorsport's Will Macintyre in ninth, and the final driver within a second of Slater's ultimate pace.
Reigning F1 Academy champion Abbi Pulling completed the day's top-10. A total of 23 drivers participated in today's test, with Hillspeed providing tests for Formula Regional racers Kanato Le and Hiyu Yamakoshi.
GB3's next official action will be at Silverstone on Thursday and Friday next week (24/25 April), with pre-event testing ahead of the season opener on 26/27 April.
GB3 Championship, partnered by the BRDC, Brands Hatch GP Official Test result:
1. Freddie Slater, Hillspeed, 1m19.633s
2. Alex Ninovic, Rodin Motorsport, +0.125s
3. Gianmarco Pradel, Rodin Motorsport, +0.371s
4. Deagen Fairclough, Hitech TGR, +0.472s
5. James Higgins, Fortec Motorsports, +0.599s
6. Reza Seewooruthun, Argenti with Prema, +0.828s
7. Kai Daryanani, JHR Developments, +0.906s
8. Patrick Heuzenroder, Xcel Motorsport, +0.945s
9. Will Macintyre, Elite Motorsport, +0.967s
10. Abbi Pulling, Rodin Motorsport, +1.129s
11. Dion Gowda, Xcel Motorsport, +1.145s
12. Jack Sherwood, Xcel Motorsport, +1.206s
13. Hugo Schwarze, VRD Racing, +1.229s
14. Stefan Bostandjiev, Fortec Motorsport, +1.343s
15. Kanato Le, Hillspeed, +1.361s
16. Yuanpu Cui, Argenti with Prema, +1.427s
17. Hiyu Yamakoshi, Hillspeed, +1.453s
18. Nikita Johnson, Hitech TGR, +1.839s
19. Keanu Al Azhari, Hitech TGR, +1.847s
20. Noah Lisle, JHR Developments, +1.962s
21. Flynn Jackes, Elite Motorsport, +2.254s
22. Rashid Al Dhaheri, Chris Dittmann Racing, +2.479s
23. Bianca Bustamante, Elite Motorsport, +4.022s