MONZA (REUTERS) - Lewis Hamilton won the Italian Grand Prix for Mercedes on Sunday to cut team mate Nico Rosberg's Formula One championship lead to 22 points.

After problems at the start dropped him down to fourth place from pole position, the Briton battled back to pile pressure on the German and retake the lead when Rosberg missed the first chicane on lap 29 of 53.

Rosberg now has 238 points to Hamilton's 216 with six races remaining.

The drivers will next race at the Singapore Airlines Singapore Grand Prix on Sept 21.

Brazilian Felipe Massa finished third for Williams while Finnish team-mate Valtteri Bottas was fourth.

Ferrari's Fernando Alonso retired from his team's home race while Kimi Raikkonen finished ninth.