Fernando Alonso put McLaren team-mate Lewis Hamilton in the shade by setting the fastest time during the first practice session for the US Grand Prix at Indianapolis.

Alonso, beaten last time out by Hamilton in Canada, set the fastest time and Nick Heidfeld relegated Hamilton to third quickest.

Alonso clocked one minute 11.925 seconds around the Indianapolis Motor Speedway as preparations began in earnest for tomorrow's US GP,

The Spanish double world champion was 0.466secs faster than BMW Sauber driver Heidfeld, who had claimed second place in Canada last week behind McLaren rookie Hamilton.

Heidfeld split the McLarens with Hamilton, who had never seen the track before yesterday, managing a best lap of 1:12.628 from his first 21 laps on the famous circuit.

There was more bad news for Ferrari, trailing McLaren in the constructors' championship by 28 points.

Both Kimi Raikkonen and Felipe Massa were outpaced in the opening session by Sebastian Vettel, the 19-year-old BMW Sauber test driver who will make his GP debut tomorrow.

The German teenager is a replacement for Robert Kubica, who was stood down by Formula One and race doctors following his spectacular accident in Montreal last Sunday.

Vettel clocked 1:12.869, the fourth fastest of the session, with Raikkonen the quicker of the two Ferraris with 1:12.966, 1.041secs slower than Alonso.

Massa, disqualified last week in Canada for jumping a pit lane red light, managed seventh fastest in 1:13.040, 0.02secs behind the Williams of Nico Rosberg.

Britain's David Coulthard (1:13.159) of Red Bull Racing was eighth fastest, followed by Honda's Jenson Button (1:13.597), with Coulthard's team-mate Mark Webber of Australia rounding out the top-ten (1:13.682).

Super Aguri's Anthony Davidson ran 20th of the 22 drivers in 1:14.632 but managed only ten laps during the 90-minute session.

Alexander Wurz sat out the session, allowing Williams to give test driver Kazuki Nakajima lap time, while Spyker's Adrian Sutil spun out on the chequered-flag lap and was unable to escape the gravel.

Ferrari star Massa, meanwhile, has vowed to bridge the gap on Formula One front-runners McLaren.

Ferrari won three of the first four races of the season, with Raikkonen taking the opening Australian Grand Prix and Massa winning in Bahrain and Spain.

Then the Ferrari campaign hit the skids, with the team drubbed in Monaco as McLaren's Alonso and Hamilton secured their one-two finish.

Then Massa was disqualified in Canada last weekend as the Brazilian ran a red light exiting the pit lane and Raikkonen was outpaced by Heidfeld, the Williams of Alexander Wurz and Renault's Heikki Kovalainen as the Finn had to settle for fifth behind race winner Hamilton.

McLaren have a 28-point lead over Ferrari in the constructors' championship, the sort of dominance enjoyed by the Italian team at the Indianapolis Motor Speedway since 2000, with Michael Schumacher winning six of the seven Grands Prix at the venue.

Massa sees that as a good omen.

''I expect a very good weekend,'' said Massa.

''We were one-two here last year and I expect to have a good race this year. I think our car will go much better.''

Massa is not daunted by the size of McLaren's lead in the constructors' championship or his third place in the drivers' championship, seven points behind second-placed Alonso and 15 adrift of Hamilton.

''At the moment I am aware that the gap to the championship leader is quite big at 15 points and this is more concerning than the gap to the second-placed man, as my target of course is to win.

''Now we must try to reduce the gap and then move ahead.''