Rodin Motorsport's champion Alex Ninovic topped the times in the second free practice session of the day at Autodromo Nazionale Monza.
The Australian posted a best lap of 1m44.321s, though the final minutes of the session were red flagged after a crash for Kabir Anurag exiting Lesmo One, with the driver emerging unscathed.
Ninovic was just 0.010s ahead of Hillspeed's newcomer Maxim Rehm, who continues to make upward progress ahead of his GB3 debut this weekend, with the German's fellow debutant teammate Newman Chi was third, and less than a tenth further back.
Xcel Motorsport's Jack Sherwood was fourth quickest and 0.14s away from Ninovic's outright pace, with his teammate Patrick Heuzenroeder, who topped FP1 with the quickest time of the day, was fifth this time around.
Noah Lisle was the lead JHR runner in sixth place, just 0.005s ahead of Rodin's Gianmarco Pradel, with Anurag eighth despite his shunt.
The third Rodin of Abbi Pulling and Hitech's Deagen Fairclough completed the top-10, which was covered by less than half a second, with the top-15 drivers all within a second of each.
GB3 action resumes at Monza with the two part qualifying session starting at 10.20 on Saturday morning.
GB3 Championship, partnered by the BRDC, Autodromo Nazionale Monza, Free Practice Two result:
1. Alex Ninovic, Rodin Motorsport, 1m44.321s
2. Maxim Rehm, Hillspeed, +0.010s
3. Newman Chi, Hillspeed, +0.092s
4. Jack Sherwood, Xcel Motorsport, +0.142s
5. Patrick Heuzenroeder, Xcel Motorsport, +0.204s
6. Noah Lisle, JHR Developments, +0.280s
7. Gianmarco Pradel, Rodin Motorsport, +0.285s
8. Kabir Anurag, Xcel Motorsport, +0.315s
9. Abbi Pulling, Rodin Motorsport, +0.376s
10. Deagen Fairclough, Hitech TGR, +0.477s
11. Isaac Phelps, Elite Motorsport, +0.489s
12. Enzo Tarnvanichkul, VRD Racing, +0.789s
13. Keanu Al Azhari, Hitech TGR, +0.812s
14. Kai Daryanani, JHR Developments, +0.961s
15. Bart Harrison, JHR Developments, +0.988s
16. Rodrigo Gonzalez, VRD Racing, +1.021s
17. August Raber, Argenti with Prema, +1.207s
18. Lucas Fluxa, Argenti with Prema, +1.243s
19. Bianca Bustamante, Elite Motorsport, +1.602s
20. Patricio Gonzalez, VRD Racing, +1.932s
21. Flynn Jackes, Elite Motorsport, +2.577s
22. Reza Seewooruthun, Argenti with Prema, no time set