Mark Webber heads European Grand Prix first practice

Webber is targeting his second pole position of the season in Valencia

Mark Webber kept Red Bull on top of the timesheets as he led first practice for the European Grand Prix in Valencia.

The Australian was 0.824 seconds ahead of Vitaly Petrov's Renault with Ferrari's Fernando Alonso third.

McLaren ran an updated car and Lewis Hamilton was fourth with Jenson Button seventh, and Red Bull's championship leader Sebastian Vettel 16th.

Force India reserve Nico Hulkenberg, who was in Scot Paul di Resta's car, crashed out of the session.

The thrilling Canadian Grand Prix has given fresh hope that, despite Red Bull's dominance, the championship is by no means settled with 12 races still to go.

Vettel has a 60-point advantage over Button but Red Bull's closest rivals McLaren and Ferrari trialled new parts in Valencia in an attempt to gain ground.

McLaren ran with new front wing end-plates and daubed 'flo-viz' paint over a modified rear wing to see if the alteration generated any extra downforce.

The modifications meant Hamilton ran without the DRS overtaking device during the session.

BBC pit-lane reporter Ted Kravitz explained: "There's a nice curve in the rear wing because it's a tweak on the DRS that McLaren are testing.

"While their [old specification] rear wing does give them better downforce it is still about 5mph down on the best DRS in the pit lane when it's activated."

Hamilton, who had shrugged off suggestions that he needed to make amends for two disappointing races in Valencia, was just over a second shy of Webber's leading time.

Button had a low-key session and was almost 0.5secs slower than his McLaren team-mate.

Ferrari also tried out a modified front wing, which was split into two front tiers instead of three, and an updated rear suspension.

However, the F1 paddock is also wondering whether two new directives from F1's governing body, the FIA, will also narrow Red Bull's advantage in the coming races.

The FIA wrote to the teams before the European Grand Prix to explain that they will no longer be able to change their engine maps - how the engine governs the car's fuel usage - between qualifying and the race.

Vettel, who has won five out of seven races this season, was 18th fastest in first practice

At the next race at Silverstone on 10 July, the use of so-called off-throttle blowing of diffusers, which help to increase downforce by blowing hot gasses over the rear of the car's floor while the driver is not pressing the accelerate, will be banned.

Red Bull team boss Christian Horner confirmed that the team would trial a Silverstone specification during practice in Valencia, leading to suggestions that was why Vettel was 2.5secs off his team-mate's leading time.

Valencia's street circuit, which skirts along the Juan Carlos 1 marina, evolves significantly over the race weekend and there was plenty of dust and dirt as the drivers found their rhythm.

Despite some wobbles from Virgin driver Timo Glock and Mercedes driver Michael Schumacher, Force India reserve Hulkenberg was the only driver to fall foul of the 'green' track, hitting the wall within the first half an hour.

"The rear snapped on him and he tried to correct it but ran out of road," explained BBC 5live analyst Anthony Davidson.

"It shows when you're not in the car very often it's difficult to get back up to speed."

Sergio Perez returned for Sauber after sitting out the Canadian Grand Prix because of the after effects of his heavy crash in Monaco.

The Mexican was 14th fastest and the team are hopeful he will be fit enough to race, adding that Perez said he felt fine during the practice session in Valencia.