Rubens Barrichello was 0.128 slower than Montoya in second place, while Schumacher was third with 1:20.784.
The Ferrari driver is one point ahead of Williams's Juan Pablo Montoya and two clear of McLaren's Kimi Raikkonen with two races remaining after Monza.\n\n
David Coulthard grabbed second place for McLaren, ahead of Jarno Trulli and Fernando Alonso in the two Renaults.
The Colombian staunchly defended his attempt to steal pole position from team mate Kimi Raikkonen at the German Grand Prix despite ending up in the trackside gravel.
Jordan's Sporting Director Adrian Burgess said though the Indian is doing a "fantastic" job, luck is not on his side.
Briton Jenson Button will be docked 10 places on the starting grid for having his BAR's engine replaced.
Williams's Formula One championship challenge is on after they ousted McLaren as Ferrari's closest rivals.
Carlos Tevez scored from a free kick for the second game in a row in a 3-0 win in the Copa America football semi-final.
Germany's Ralf Schumacher relived the worst accident of his F1 career as Juan Pablo Montoya set the pace in U.S. Grand Prix practice.
Ferrari's six-times world champion Michael Schumacher starts Sunday's Canadian Grand Prix on the third row in sixth place.
McLaren's Juan Pablo Montoya, returning to Formula One after missing two races due to injury, crashed heavily in practice.
The McLaren driver will make his return in Sunday's race, subject to final medical approval on Friday.
Williams pushed their luck and paid the price in Sunday's Spanish Formula One Grand Prix as Juan Pablo Montoya and Ralf Schumacher wrestled with brake problems.
Michael Schumacher of Germany, driving a Ferrari, has won the San Marino Formula One Grand Prix.
The former McLaren Formula One driver's car was tapped from behind on lap 252 of a 267-lap race at the Miami Speedway.
A man playing a practical joke by wearing a Laden mask and jumping out at motorists was shot by a startled taxi driver in Costa Rica.
Federico Montoya will drive for the Berlin-based Muecke team in the German Formula BMW series next year.
The German won a wet and wild US Grand Prix while Colombian rival Juan Pablo Montoya's title hopes were blown away.
The Italian clocked the fastest qualifying lap in first qualifying for Sunday's U.S. Grand Prix.\n\n
Ferrari's Michael Schumacher can win a record sixth Formula One championship at Indianapolis on Sunday if circumstances go his way.
The defending F1 champion expects the title to be decided by a last-race duel between himself and the Colombian.
The German world champion now has 82 points to second-placed Montoya's 79.
Ferrari's ace is resigned to the idea of his younger brother helping the Colombian become world champion at his expense.