|© Charles Coates/LAT Photographic/Williams
Pastor Maldonado of Williams set the fastest lap in the first practice session Friday for the European Grand Prix.
The Venezuelan driver, who earned his first win in May at the Spanish Grand Prix in Barcelona, clocked a lap of 1:40.890 through the 25 turns of the 5.4-kilometer Valencia Street Circuit.
Two-time defending world champion Sebastian Vettel was next, followed by Red Bull teammate Mark Webber, McLaren's Jenson Button and Fernando Alonso of Ferrari. Seven-time champion Michael Schumacher was seventh, and points leader Lewis Hamilton recorded the eighth fastest time.
Vettel, who has won here the past two years after starting from pole, almost snatched top spot from Maldonado with a strong run just as the chequered flag came out. The German driver's last lap was just 0.083 seconds off the pace.
Webber spent most of the early part of the one-and-a-half hour session watching his Red Bull mechanics tinker with his car. But once on the track, he quickly found his form and posted a time just 0.094 seconds behind Maldonado.
The morning's busiest drivers were the Toro Rosso pair of Daniel Riccardio, who ran a session-high 28 laps, while Jean-Eric Vergne put in 27.
The incident-free session saw temperatures reach 32 degrees Celsius (90 F) on the track, while winds kicked up surf along the America's Cup harbour.
McLaren's Jenson Button was forced into the pits due to braking problems midway through practice, telling his team by radio: "unbelievable amount of front locking, I can't control it."
The former champion later returned to the track and recovered with a strong run for the fourth fastest time.
The session saw two test drivers get behind the wheel. Williams' Valtteri Bottas drove for Bruno Senna while Jules Branch stepped in for Force India's Nico Hulkenberg.
There will be a second session Friday afternoon, followed by a final practice on Saturday before qualifying. Sunday's race will be the eighth Grand Prix of the season.
After seven different winners in as many races, the championship is tightly contested with only three points separating Hamilton from Alonso and Vettel at the top of the standings.