Mark Webber kept Red Bull Racing at the front of the field even as the Milton Keynes team chased solutions to impending changes to the diffuser rules, leading the F1 field by 0.8secs in the opening free practice session for the European Grand Prix.
While Sebastian Vettel allegedly tried out developments set to be introduced at Silverstone next month, the Australian pounded around the Valencia street circuit, working through preparations for round eight of the 2011 season, eventually completing 22 laps with a best time of 1min 40.403secs. That left him comfortably clear at the top of the timesheets, with closest rivals Vitaly Petrov and Fernando Alonso unable to join him under 1min 41secs.
The Russian burned his back early in the 90-minute session, but returned to the track to claim second place for Lotus-Renault in 1min 41.227secs. On a circuit that should suit the Renault, it was enough to keep Petrov narrowly ahead of Alonso - who has yet to record a top five finish at his 'other' home race - as the Spanish Ferrari driver posted a 1min 41.239secs best.
Lewis Hamilton was fourth fastest for McLaren, despite conducting an aero comparison early on that prevented him from utilising the DRS system on his car. The Briton was around three tenths shy of Alonso - and the first man over a second behind Webber's benchmark - and had the second Renault of Nick Heidfeld for close company as the German rounded out the top five.
Behind him, Felipe Massa underlined Ferrari's early potential in sixth, with Jenson Button, Adrian Sutil, Nico Rosberg and Jaime Alguersuari rounding out the top ten. The younger Spaniard had just enough to prevent Michael Schumacher from making it two Mercedes in the top ten, but knows that he will have to keep up the performance at Toro Rosso to prevent his seat coming under further scrutiny this season. Team-mate - and likely replacement, Daniel Ricciardo sandwiched Schumacher in twelfth, just a couple of tenths off Alguersuari, and put himself ahead of Rubens Barrichello, Sergio Perez, Pastor Maldonado and Vettel, who managed only 16th with his alternative workload.
Kamui Kobayashi was next up, just ahead of Nico Hulkenberg, who completed just seven laps in place of Paul di Resta before crashing the Scot's car. Hulkenberg, who raced in Valencia last season with Williams, had already flat-spotted a front tyre before the incident, but was caught out by the dust that coated the circuit and was spat into the retaining wall.
The only other driver making an early exit from the session was the luckless Karun Chandhok, who saw another FP1 appearance with Team Lotus ended after just two laps by gearbox failure. The Indian had yet to set a time before second gear disappeared and, with Jarno Trulli needing the car in session two, his appearance was once again brief.
Team-mate Heikki Kovalainen was 19th fastest, ahead of both Marussia Virgin entries, with local team Hispania 22nd and 23rd with Tonio Liuzzi and Narain Karthikeyan, although the Indian was over a second behind his team-mate as he learned the circuit for the first time.