Red Bull blaze trail

German title hopeful Vettel lapped in a minute 20.976, 0.13s quicker than Australian Webber, who like Vettel is on 136 points in the World Championship.

The Milton Keynes-based outfit were over a second faster than nearest competitor Robert Kubica of Renault and almost 1.5s quicker than Jenson Button of McLaren in fourth.

Reigning world champion Button's McLaren team-mate Lewis Hamilton, the current standings leader, was all the way down in 18th - three seconds off the pace - on a sunny day near Budapest.

After a quiet first half-hour due to the green, dusty nature of the underused Hungaroring, Webber took over at the summit of the timesheets. He and Vettel swapped P1 a couple of times but were fairly close together when running simultaneously.

Their front wing, which has passed FIA tests as the movement helpful to aerodynamics only occurs when the car is in motion, is much closer to the ground than that of the championship-leading McLarens, Ferraris and most other teams.

"The bit between the nose... has passed the FIA tests so we are not worried about it," said team principal Christian Horner during the opening stages of the session.

"First it was the rear suspension that was an issue, and it will be something else next time... the front wing is behaving in a way that the guys have been clever enough to design.

"The front wing is not the only reason why the car is fast. We were surprised by how much fuss was made over it when others are running similar concepts."

The outright pace of the team will worry Ferrari and McLaren in particular, although Horner was at pains to suggest that the Scuderia have been on the pace for some time now and were even a "sniff faster" at Hockenheim last weekend.

Hamilton completed only 15 laps, half that of Vettel and the least of anyone in the field, but suffered from tyre degradation nonetheless as he wrestled the MP4-25 around the penultimate hairpin late on.

He was the slowest of the 'main' F1 teams, with only the six drivers of the debuting outfits - Lotus, Virgin and Hispania, in that order - below him in the timesheets.

Rubens Barrichello was fifth, three-tenths faster than Williams team-mate Nico Hulkenberg in 10th, while Sauber's Pedro de la Rosa impressed in sixth. He was followed by Fernando Alonso, 1.8s off Vettel's mark, and the Mercedes drivers.

In that all-German battle, the endeavour of 25-year-old Nico Rosberg triumphed over the experience of seven-times champion Michael Schumacher by 0.15s.

Alonso's Ferrari team-mate Felipe Massa was 12th on his return to the track where he suffered a frightening, life-threatening crash a year ago.