Norman Nato and Carlos Sainz Jr made it a DAMS one-two in Formula Renault 3.5 free practice on the streets of Monaco on Thursday morning.
While championship leader Sainz spent the entire session as one of the leading runners, regularly trading places at the top with 2013 Monte Carlo podium finisher Jazeman Jaafar, Nato strung a lap together with around 10 minutes remaining to go fastest.
The Frenchman's effort put him clear of Sainz by just 0.040 seconds, while ISR's Jaafar finished the session half a second down on the DAMS cars as best of the rest in third.
Sauber Formula 1 test driver Sergey Sirotkin was next up ahead of Pietro Fantin, who had also enjoyed a brief spell on top in the early part of the session.
Behind Zoel Amberg in sixth came Sainz's main title challenger Oliver Rowland, who is making his Monaco debut this weekend.
Of the other leading drivers in the title race, Pierre Gasly and Will Stevens were 13th and 14th respectively. Nikolay Martsenko, currently fifth in the standings, is not racing with Comtec this weekend.
The session was relatively incident free, with Luca Ghiotto the only driver to crash when he understeered into the barriers at Ste Devote after 18 of the 45 minutes.
Pos Driver Team Time Gap 1. Norman Nato DAMS 1m24.649s 2. Carlos Sainz Jr DAMS 1m24.689s +0.040s 3. Jazeman Jaafar ISR 1m25.262s +0.613s 4. Sergey Sirotkin Fortec 1m25.365s +0.716s 5. Pietro Fantin Draco 1m25.369s +0.720s 6. Zoel Amberg AVF 1m25.390s +0.741s 7. Oliver Rowland Fortec 1m25.489s +0.840s 8. Will Buller Arden 1m25.890s +1.241s 9. Marco Sorensen Tech 1 1m26.228s +1.579s 10. Matthieu Vaxiviere Lotus 1m26.251s +1.602s 11. Matias Laine Strakka 1m26.271s +1.622s 12. Marlon Stockinger Lotus 1m26.495s +1.846s 13. Pierre Gasly Arden 1m26.558s +1.909s 14. Will Stevens Strakka 1m26.653s +2.004s 15. Roberto Merhi Zeta 1m26.950s +2.301s 16. Roman Mavlanov Zeta 1m27.489s +2.840s 17. Beitske Visser AVF 1m27.492s +2.843s 18. Oliver Webb Pons 1m27.528s +2.879s 19. Meindert van Buuren Pons 1m28.781s +4.132s 20. Luca Ghiotto Draco 1m28.933s +4.284s 21. Andrea Roda Comtec 1m35.486s +10.837s