Esteban Gutierrez claimed his first GP2 Series win for a year in an eventful feature race in Valencia, in which the first of three safety car interventions destroyed James Calado's faultless drive to victory.
Racing Steps Foundation-backed rookie Calado made a superb getaway from pole position and quickly built up a good-sized lead as those behind him scrapped with each other.
His Lotus GP team left him out longer before calling him in for his mandatory pitstop, and this strategy backfired badly when the safety car came out after Tom Dillmann lost his rear wing and it was run over by Rodolfo Gonzalez, spraying debris all over the circuit at turn seven.
While the safety car picked Calado up, any remaining frontrunners who had not made their stops were able to so. This led to him dropping out of the lead and down the order when he eventually made his stop.
Felipe Nasr had made a bad start from alongside Calado on the front row, allowing Giedo van der Garde and Gutierrez through into second and third. Behind, Jolyon Palmer spun at turn three, being collected by fellow Englishman Max Chilton.
Van der Garde began struggling with his tyres, with Gutierrez and Fabio Leimer trying to find a way past. They would come together at the turn 17 hairpin after Gutierrez seemingly missed his braking point, with Leimer capitalising to move past both.
Van der Garde was then the first of the leaders to stop, and suffered drama in the pitlane when his right-rear wheel gun wouldn't come off, and then once he did get going he had a person step off the pit wall in front of him, causing him to slow as they escaped a collision. The Dutchman later had Luiz Razia rejoin from the pits just ahead of him, shortly before the safety car came out.
Leimer and Marcus Ericsson took advantage of the safety car to make their stops and hold second and fourth, separated by Gutierrez and ahead of Razia and van der Garde.
When the safety car came in, it didn't stay in for long. Having struggled during the early stages of the race, Nasr slowed going onto the bridge. He didn't stay right as the field tried to get by, with Palmer making the decision to go down the inside. He braked too late and clipped Fabrizio Crestani, tipping the Italian's Venezuela GP Lazarus car into a barrel roll, from which he seemed to escape unscathed.
When the race was again restarted, Calado held the lead while Gutierrez attacked Leimer for second at the final turn. As the pair ran wide, Razia escaped with the position, which was going to become the race lead once Calado came in. Gutierrez quickly took the position however.
That soon became the lead when the safety car came out for a third time, this time after Gonzalez had hit fellow Venezuelan tailender Giancarlo Serenelli off at turn 14 – the same point Gonzalez had spun it on his own early in Friday's practice session.
With the clock ticking down, Calado used that opportunity to make his stop, rejoining in tenth place. This handed Gutierrez the lead, with Ericsson moving up into second ahead of Razia and Leimer. That was how it remained in the closing laps after the final restart, with Gutierrez setting the fastest lap on the final lap of the race as he took his second GP2 win, his first having come in last year's sprint race.
Ericsson finished second for the second feature race in succession, unable to end his own winless draught that stretches back two years to Valencia 2010. Razia held off Leimer for the final place on the podium.
Rookie Rio Haryanto drove a mature race as much of the field lost their heads, finishing right behind Leimer in fifth place. Leimer and Haryanto's teammates at Racing Engineering and Carlin, Nathanael Berthon and Chilton, finished next up.
Johnny Cecotto crossed the line in eighth place for home team Addax, but was handed a stop-go penalty in the final couple of minutes for an unsafe release. This resulted in him having 30 seconds added to his time and relegating him to 19th place and the last car on the lead lap.
This promoted championship leader Davide Valsecchi to eighth place and a vital reverse grid pole position for the sprint race, to rescue his weekend after a terrible opening lap that saw the Italian drop from sixth on the grid to 15th place. Razia's third place brought the gap between the two down from 31 points to 20, but Valsecchi will look to use his reverse grid pole to open that up again.
Calado had a sniff of salvaging something from his race and attempted to pass Valsecchi at the end but couldn't get by and had to settle for ninth.
Stefano Coletti was tenth, leading home Simon Trummer and van der Garde – who made a second stop after suffering a massive lockup as he tried to pass Razia for fifth at the first restart, ruining the front tyres that his Caterham team had opted not to change at his earlier stop.
Julian Leal, Fabio Onidi and Stepahane Richelmi followed closely behind, ahead of Josef Kral, Gonzalez and debutant Daniel De Jong.
Victor Guerin ended up a lap down after failing to get away from his pitstop, on a miserable day for Ocean Racing Technology who saw Nigel Melker crash out on the second lap.
The sprint race takes place at 09:35 BST on Sunday.