Despite appearing in the lower reaches of the free practice timesheet, ART Grand Prix's Nico Hulkenberg bounced back to claim his first 'summer series' GP2 pole position in qualifying for the Istanbul round.

The German produced a forceful display of power and finesse in the afternoon qualifying session, taking the top spot by a tenth from both Luca Filippi and points leader Romain Grosjean. The rookie bided his time throughout the session before unleashing a lap of 1min 34.404secs, setting all three fastest sectors, with just five minutes remaining.

His timing could not have been better as, with Vitaly Petrov and ART team-mate Pastor Maldonado stopping on track with mechanical gremlins almost immediately afterwards, two yellow flag zones appeared and the session was effectively over.

With the drivers again taking to the track in steaming conditions, H?lkenberg set an early quick lap, before Petrov took over top spot. The Russian driver initially looked untouchable, but his competitors kept nibbling away at his time, with Lucas di Grassi, Filippi and Karun Chandhok all closing in from behind.

It was Grosjean, however, who finally bested his team-mate with six minutes remaining, but H?lkenberg was already on a charge, taking the top spot seconds later with Filippi in tow. Petrov then suddenly slowed from what had been a quick looking lap, pulling off to the side of the track, and, when Maldonado's car started smoking, there was no chance for anyone else to improve their times.

Despite his disappointment, Petrov will nevertheless start from fourth in Saturday's feature race, ahead of Chandhok, Andreas Zuber and morning pacesetter Alvaro Parente. Javi Villa, Roldan Rodriguez and Davide Valsecchi round out the top ten, meaning that several leading lights find themselves lower down the order than expected - and others will sink lower following a rash of penalties handed out after practice.

Maldonado ended the session 13th, but will move up one spot - as will Lucas di Grassi - when Giedo van der Garde drops three for speeding under yellows. Asian Series champion Kamui Kobayashi struggled again in qualifying, and registered only 17th place, but will benefit from Edoardo Mortara getting a copy of van der Garde's punishment. iSport's Diego Nunes was the third driver handed a three-place penalty, having qualified 18th, while Dani Clos blotted his copybook to the tune of ten spots after ignoring marshals' requests to vacate his spun car early in practice. The Spaniard will now start at the back, having qualified only 22nd.

Intriguingly, however, Grosjean appears to have got away with leaving the track - rather than just speeding - in an area marked by yellow flags....