Juan Pablo Montoya controlled today's Italian Grand Prix from start to finish – but Fernando Alonso finished second to extend his world championship advantage to 27 points with only 40 still to play for.

Montoya's team-mate Kimi Raikkonen set the fastest qualifying time, but he was pushed back 10 places on the grid after having an unscheduled pre-race engine change. The Colombian scorched into the lead from pole and resisted early pressure from fellow front-row starter Alonso, although the Spaniard closed in again towards the end of the race.

Raikkonen took fourth place behind Alonso's team-mate Giancarlo Fisichella, who picked his way through the field after qualifying eighth on a heavy fuel load.

Toyota team-mates Jarno Trulli and Ralf Schumacher finished fifth and sixth, while Williams-BMW stand-in Antonio Pizzonia completed a weekend to remember with a strong run to seventh. The Brazilian hadn't raced an F1 car for a year – and hadn't driven one at all for almost three months – but he was called up to replace Nick Heidfeld after the latter began suffering headaches during Friday's free practice. These are thought to be a corollary of a recent testing accident at the Milanese track. Pizzonia qualified only 16th, but he made steady, flawless progress to pip BAR-Honda star Jenson Button to seventh place.

Sauber drivers Felipe Massa and Jacques Villeneuve finished ninth and 11th, either side of Michael Schumacher's Ferrari. The German, who has been world champion since October 8 2000, is now officially out of the reckoning in this year's world championship fight after five straight title successes.

All 20 starters finished the race – the first time there have been no retirements from a world championship grand prix since Holland 1961.

Of the other Michelin runners, Christian Klien was 13th ahead of Mark Webber, David Coulthard and Takuma Sato. Webber and Coulthard had to make pit stops after a first-lap clash, while Sato – who started alongside team-mate Button on row two – lost time because of a refuelling problem during his first scheduled stop.

Pierre Dupasquier, Michelin motorsport director: "Despite McLaren's magnificent victory, the team obviously had some kind of tyre issue today. When we saw Kimi Räi kkönen's cut left rear we were curious about the cause, but Montoya's late-race incident illustrates there was a problem of some kind and we will look at this closely with our colleagues from McLaren.

"Tyre wear on the outside edge of a carcase is extremely unusual here – normally it's the inside shoulder that bears the bulk of the load down the long straights. We had no problems at illustrates why F1 should remain an open competition between rival companies."

Nick Shorrock, director of Michelin F1 activities: "The overnight rain didn't change the nature of the track a great deal. All our cars ran on the same tyre compound and the race panned out according to plan, with the exception of two specific incidents. Despite those, however, McLaren scored a terrific win – and it was another fantastic result for us."

Ron Dennis, McLaren Group chairman: "We obviously had some delamination trouble with both cars– but the problem was probably down to our set-up rather than the tyres. That's just part of the sport. Michelin chose the best tyre compound for this race, in my opinion, and despite the difficulties we were able to score a great victory."