Johnny Cecotto Jr will start round seven of the GP2 Series in Monaco from pole position after topping his qualifying session for odd-numbered cars.
But Arden team-mate Mitch Evans came within 0.016 seconds of toppling him in the second group.
The sessions were split in two, for odd- and even-numbered cars, to avoid the crashes that have occurred in recent years with all 26 cars on track simultaneously.
The flip-side was that drivers only had 15 minutes to set their times, so had just one run on the Pirelli super-soft tyres.
In Group A, last year's feature race winner Cecotto looked ragged but it was resulting in some fantastic times.
He worked his way down to 1m21.141s, some 0.368 seconds clear of second-quickest driver, and free practice pacesetter, Sam Bird of the Russian Time team.
Trident's Kevin Ceccon and Julian Leal (Racing Engineering) were next up.
In Group B, for even numbered cars, the fastest time swapped hands numerously between Tom Dillmann, Mitch Evans, Jolyon Palmer and Fabio Leimer.
Evans was at the top when the chequered flag fell, but his 1m21.157s was just 0.016s slower than Cecotto's earlier mark.
Cecotto thus earned the Group A runners the cleaner left-hand side of the grid. He will start with Evans alongside him, with row two comprising Bird and Leimer (Racing Engineering).
Ceccon and Palmer (Carlin) will share row three, ahead of Leal and Dillmann (Russian Time).
Frontrunners Felipe Nasr and Robin Frijns will start ninth and 10th, with points leader Stefano Coletti down in 14th.
Pos Driver Team Time 1. Johnny Cecotto Jr Arden 1m21.141s Group A 2. Mitch Evans Arden 1m21.157s Group B 3. Sam Bird Russian Time 1m21.509s Group A 4. Fabio Leimer Racing Engineering 1m21.185s Group B 5. Kevin Ceccon Trident 1m21.986s Group A 6. Jolyon Palmer Carlin 1m21.198s Group B 7. Julian Leal Racing Engineering 1m22.092s Group A 8. Tom Dillmann Russian Time 1m21.387s Group B 9. Felipe Nasr Carlin 1m22.163s Group A 10. Robin Frijns Hilmer 1m21.418s Group B 11. Marcus Ericsson DAMS 1m22.349s Group A 12. Sergio Canamasas Caterham 1m21.522s Group B 13. Alexander Rossi Caterham 1m22.511s Group A 14. Stefano Coletti Rapax 1m21.658s Group B 15. Rio Haryanto Addax 1m22.589s Group A 16. Nathanael Berthon Trident 1m22.245s Group B 17. James Calado ART 1m22.677s Group A 18. Stephane Richelmi DAMS 1m22.317s Group B 19. Daniel de Jong MP 1m22.943s Group A 20. Rene Binder Lazarus 1m22.376s Group B 21. Kevin Giovesi Lazarus 1m23.006s Group A 22. Daniel Abt ART 1m22.716s Group B 23. Simon Trummer Rapax 1m23.017s Group A 24. Jake Rosenzweig Addax 1m22.842s Group B 25. Jon Lancaster Hilmer 1m23.443s Group A 26. Adrian Quaife-Hobbs MP 1m23.328s Group B