Rosberg, also 31, has the luxury, however, of knowing that he does not have to win again this season to clinch his first world title. Four second-place finishes behind Hamilton will be enough.
On a hot late summer`s day at the old Autodromo Nazionale in Monza`s former royal park, the 31-year-old Briton clocked a best lap in one minute and 22.801 seconds to outpace German Rosberg by 0.193 seconds.
Hamilton leads Rosberg by nine points going into the last European race of the season but can hope to extend that on Sunday.
He finished runner-up to Lewis Hamilton in the 2008 world championship by 1 point.
The aftermath of that three-way shunt is likely to continue to reverberate at Monza as the drivers and teams try to prove their positions before moving on.
Hamilton leads Drivers' standings with 232 points to Rosberg`s 223.
Nico Hulkenberg and Sergio Perez bagged 22 points by finishing fourth and fifth.
Hamilton produced a fantastic drive in an action-packed race, despite starting from the back row of the grid, to finish third.
The Dane lost control of his car as he crested the fast uphill sweep of the Eau Rouge corner and slammed violently into the barriers.
Triple world champion Hamilton, who has a 19-point cushion over team mate Nico Rosberg at the top of the drivers` standings, appeared relaxed though.
It was Rosberg`s fifth pole this season and the 28th of his career - and gives him a great chance to reduce, or even overhaul, Hamilton`s 19-point lead in the drivers` title race.
The 18-year-old Red Bull driver clocked a best lap of one minute and 48.085 seconds.
"For me, it`s probably the best team I`ve been with in my career.
The three-time world champion leads this year`s title race by 19 points from team-mate Nico Rosberg.
Crutchlow is the first Briton to win an elite-class Grand Prix since Barry Sheene in 1981.
Retirement is still far away, I only hope that I will decide it and not my body.