Nico Rosberg led the way in opening practice this morning for this weekend's European Grand Prix at Valencia in Spain.
Rosberg posted the quickest time, a 1 minute 41.175 seconds, with around 15 minutes of the session left to run, and that put him 0.164 seconds up on Lewis Hamilton, who was 'best of the rest' for McLaren.
As normal, proceedings got off to a slow start, and while Heikki Kovalainen was the first man out for Lotus to put in an installation lap, it wasn't until nearly 20 minutes into FP1 that Lucas di Grassi posted the first time, a 1m 49.569s.
Jenson Button then went quickest, before a wing mirror fell off Bruno Senna's Hispania and it was then subsequently run over by Sebastien Buemi. This briefly brought out the red flags, while marshals cleaned up the track.
After that running resumed as normal, and while Nico Hulkenberg grazed the wall at one point in his Williams, there were no other incidents.
In the end, Button finished the session third, just 0.044 seconds off his McLaren team-mate, while Renault's Robert Kubica and Felipe Massa's Ferrari rounded out the top five, the former the last of the runners in the 1m 41s.
Red Bull's Sebastian Vettel and Mark Webber came in sixth and seventh respectively, the Milton Keynes-based squad experimenting with their version of McLaren's F-duct. Michael Schumacher, Fernando Alonso and Rubens Barrichello completed the top ten, followed by Nico Hulkenberg and Vitaly Petrov.
Further down the order, the Force India F1 team was seemingly off the pace and Vitantonio Liuzzi and Paul di Resta, who was running in Adrian Sutil's car, were down in 14th and 16th respectively, with Sebastien Buemi ahead of both in 13th.
Pedro de la Rosa was sandwiched between the two Force India's in 15th, with his Sauber team-mate, Kamui Kobayashi two spots lower in 17th and then Jaime Alguersuari the last of the established runners in 18th.
Heikki Kovalainen was the best of the new team runners in his Lotus, three tenths off Alguersuari, while Timo Glock and Bruno Senna came in 20th and 21st and ahead of the other Lotus of Jarno Trulli.
Hispania test and reserve driver, Christian Klien and Virgin's Lucas di Grassi brought up the rear, both more than six seconds off the pace. Indeed the Hispania team had a tough time with Klien hindered by gearbox woes and Senna slowed by a driveshaft problem.
To see the full times from the European Grand Prix - Free Practice 1: CLICK HERE.