His great rival Kimi Raikkonen finishing second for McLaren after running a different strategy.

Michael Schumacher trailed home third, the Ferrari driver over a minute behind Alonso and the last man not lapped, while Jenson Button finished fourth to give the BAR-Honda team its first points of a difficult season.

Jarno Trulli was fifth for Toyota, Giancarlo Fisichella sixth in the second Renault, Ralf Schumacher seventh in the sister Toyota and Jacques Villeneuve a confidence-boosting eighth for Sauber.

Fernando Alonso led away from pole position and was never challenged all race. His position was helped in the early stages by Jarno Trulli, whose second place running Toyota clearly held up those behind.

Trulli was chased early on by the two Ferrari's, Schumacher and Rubens Barrichello heading Takuma Sato in the first of the BAR-Hondas and Fisichella.

These two had eventful races; Takuma outbraked himself at the hairpin while fighting with Trulli and left the circuit, and repeated the excursion later on when unsettled by a car in front. He finished out of the points.

Fisichella, meanwhile, continues to get the worst of the luck at Renault. His first pit stop was lengthened by a faulty fuel filler, his second by a stalled engine.

Button drove an excellent race to stay out of trouble and net points for BAR in fifth, while Trulli's pace faded later in the race and could only manage sixth.

Ralf Schumacher drove well to bring the second Toyota home in the points after his hampered qualifying, and Jacques Villeneuve drove his best race of the season for eighth.

Rubens Barrichello and David Coulthard completed the top ten.

McLaren opted to run two pit stops instead of the three taken by the other top teams, and swift work and fast driving elevated both cars into the top three by half distance.

Juan Pablo Montoya was due a fine finish, but had points snatched away from him when a hydraulic problem stopped the car on lap 48.

Williams had a disappointing race. Mark Webber finished 12th having had a bucket of water deposited in the cockpit in an attempt to alleviate an unusual problem - something burning his backside - while Nick Heidfeld came home 14th having stopped to change a tyre.

Both Jordans finished, Tiago Monteiro maintaining his 100% record in 13th, Narain Karthikeyan in 15th, while both Minardis retired with what appeared to be tyre-related problems.

The other non finishers were Felipe Massa (Sauber) and Christian Klien (Red Bull) with unspecified mechanical failures.

So a largely uneventful race saw Alonso extend his World Championship lead by another two points, but Raikkonen and McLaren will be happy to have finished second after starting so far down the grid.

The pace of Michael Schumacher and the Ferrari will be of disappointment to the Maranello concern who came here expecting to be closer to the front runners, and Button will be fired up ahead of his home race next weekend.

It remains to be seen just where or when, or indeed if, Renault and Alonso will falter and allow Raikkonen and McLaren a serious shot at the title as we enter the second half of the season.