James Calado scored the second pole position of his short GP2 career after narrowly edging out fellow rookie Felipe Nasr in an intriguing session.

The session started in chaotic fashion. Points leader Davide Valsecchi was in the minority who chose to start on the supersoft tyre, and headed the queue. After his out lap he then used another lap before going for a flying lap, but despite having clear air he slowed down during the final sector. Johnny Cecotto came flying up behind him and tried to get past, only for Valsecchi to speed up and block him.

Valsecchi's efforts would come to nothing however as Giancarlo Serenelli had spun out ahead of him, bringing out the red flags.

After the restart, Valsecchi tried again and moved to the head of the timesheets, only to have his effort bettered by Esteban Gutierrez before Valsecchi's DAMS teammate Nasr then edged ahead.

Calado waited longer before emerging from the pits after the red flag, and his first effort was 0.002 seconds quicker than Nasr's.

The Racing Steps Foundation man then improved his time by five thousanths of a second to bring his advantage over Nasr up to 0.007s.

When Valsecchi returned to the pits he fitted the soft tyre that the other frontrunners had been on before, with those drivers moving to the supersoft.

None of the top positions changed before the end of the session, handing Calado pole – even if he did have a spin on the exit of the turns four and five chicane that required him to drive back the wrong way in order to safely get it pointing the right way.

Valsecchi's hopes of improving were hampered when squabbling backmarkers Rodolfo Gonzalez and Fabrizio Crestani blocked him. On a day of dubious driving by the tailenders, Gonzalez had spun into the wall during free practice while Crestani nearly caused another accident in the same session when he swerved in front of Giedo van der Garde.

The Dutchman qualified in fifth place behind Gutierrez and Valsecchi, and ahead of Max Chilton.

Fabio Leimer and Jolyon Palmer will share the fourth row of the grid, with Palmer's iSport teammate and practice pacesetter Marcus Ericsson only managing ninth this time around.

Rio Haryanto completed the top ten at the expense of title contender Luiz Razia, who overshot turn two on one of his laps.

Tom Dillmann was 12th in the car usually driven by the ill Ricardo Teixeira, ahead of Monegasque duo Stefano Coletti and Stephane Richelmi. Monaco winner Cecotto was only 15th after his early incident, ahead of Nathanael Berthon, Simon Trummer and Fabio Onidi.

Josef Kral was 19th in a disappointing session for home team Addax, ahead of Leal and, subject to any penalties they may receive for their misdemeanours, Crestani and Gonzalez. In the meantime Ocean drivers Nigel Melker and Victor Guerin will have to make to do with 23rd and 24th, with debutant Daniel De Jong the slowest of those to set a time in 25th with Serenelli set to start last after failing to record a time.

The feature race takes place at 14:40 BST on Saturday.