Casey Stoner boosted his hopes of narrowing Valentino Rossi's big MotoGP championship lead in Sunday's San Marino Gran Prix when he took pole position in qualifying on Saturday.

The Australian world champion lapped in 1:33.378 on his Ducati, over a half a second faster than Rossi's best of 1:33.888 and despite suffering a hand fracture in Friday's practice sessions.

"Hopefully it'll be OK tomorrow," Stoner, who won the San Marino race last year, told Mediaset television when asked about the injury after taking his seventh consecutive pole. "We've been strapping it up. It's not too bad."

Italian Rossi, who is 50 points ahead of Stoner in the standings after taking his total up to 237 with wins in the preceding races in the Czech Republic and the United States, will be joined on the front row by his Yamaha team mate Jorge Lorenzo.

Spaniard Lorenzo, who made a strong start to his debut season in MotoGP but has struggled in recent races after a series of falls, recorded a best lap of 1:33.964 at the Misano circuit near Rimini in Italy.

French Honda rider Randy de Puniet is fourth on the grid, while Toni Elias qualified fifth on his Ducati.

Spain's Honda rider Dani Pedrosa, who is third in the standings with 172 points, completes the second row.

In the 250cc class, Spain's Aprilia rider Hector Barbera will start at the front of the field with Italy's championship leader Marco Simoncelli in second place on his Gilera.

Hungary's defending champion Gabor Talmacsi took pole on his Aprilia in the 125cc class ahead of Britain's Bradley Smith, with French championship leader Mike di Meglio sixth on the grid.