Sam Bird set the fastest time in the half-hour practice session for the fourth race weekend of the GP2 Series season on the streets of Monaco.
Using the super-soft tire, Bird lapped the Principality in 1m21.512s, leading a Russian Time one-two ahead of team-mate Tom Dillmann, who was 0.057sec slower.
Bird rates the Monaco track as his favorite on the calendar, and won here in Formula Renault 3.5 last season.
Mitch Evans was best of the rest for Arden in third, almost a quarter of a second off Bird's pace. Jolyon Palmer was fourth fastest for Carlin, but was unable to break into the 1m21s bracket.
Barcelona poleman Marcus Ericsson was fifth fastest for DAMS, ahead of Johnny Cecotto Jr., Fabio Leimer, Felipe Nasr, Rio Haryanto and James Calado, who suffered an overshoot at Ste Devote near the end of the session.
The drivers were very well behaved in the session, with only a couple of moments to report. Local hero Stephane Richelmi spun at Rascasse, and then stalled as he attempted to recover, ending the session 19th.
Nasr had the nearest of misses at the Swimming Pool, while championship protagonists Leimer and Stefano Coletti suffered overshoots; Leimer at Ste Devote, Coletti at Nouvelle Chicane. Kevin Giovesi also slid to a halt at Rascasse.
Championship leader Coletti, who hails from Monaco, ended the session down in 17th. Barcelona feature race winner Robin Frijns was even slower, down in 20th and 2.1s off the pace.
Pos Driver Team Time Gap Laps
1. Sam Bird Russian Time 1m21.512s 15
2. Tom Dillmann Russian Time 1m21.569s + 0.057s 18
3. Mitch Evans Arden 1m21.754s + 0.242s 17
4. Jolyon Palmer Carlin 1m22.059s + 0.547s 19
5. Marcus Ericsson DAMS 1m22.290s + 0.778s 18
6. Johnny Cecotto Jr Arden 1m22.391s + 0.879s 15
7. Fabio Leimer Racing Engineering 1m22.499s + 0.987s 13
8. Felipe Nasr Carlin 1m22.516s + 1.004s 17
9. Rio Haryanto Addax 1m22.578s + 1.066s 16
10. James Calado ART 1m22.647s + 1.135s 18
11. Julian Leal Racing Engineering 1m22.795s + 1.283s 18
12. Kevin Ceccon Trident 1m22.872s + 1.360s 18
13. Alexander Rossi Caterham 1m22.979s + 1.467s 18
14. Jake Rosenzweig Addax 1m23.251s + 1.739s 16
15. Nathanael Berthon Trident 1m23.365s + 1.853s 19
16. Sergio Canamasas Caterham 1m23.369s + 1.857s 18
17. Stefano Coletti Rapax 1m23.527s + 2.015s 17
18. Simon Trummer Rapax 1m23.633s + 2.121s 17
19. Stephane Richelmi DAMS 1m23.648s + 2.136s 10
20. Robin Frijns Hilmer 1m23.702s + 2.190s 19
21. Daniel Abt ART 1m23.854s + 2.342s 19
22. Rene Binder Lazarus 1m23.905s + 2.393s 19
23. Daniel de Jong MP 1m24.223s + 2.711s 19
24. Jon Lancaster Hilmer 1m24.600s + 3.088s 11
25. Kevin Giovesi Lazarus 1m24.755s + 3.243s 19
26. Adrian Quaife-Hobbs MP 1m24.916s + 3.404s 19