While Alonso briefly fell into the clutches of Schumacher and Hamilton, the Ferrari was able to open out a cushion, leaving the two Mercedes-powered drivers to embark on a battle that raged for 17 laps and, on occasion, came close to pushing the boundaries of the regulations. Although the McLaren was the faster car around the entire lap, Schumacher held the upper hand in terms of position, and was determined to defend it, almost at any cost. On several occasions, the German showed flashes of his old self, chopping across Hamilton's bows in the DRS zones and earning himself a couple of warnings from team principal Ross Brawn.
The Briton briefly got ahead at Rettifilio on lap 13, but almost immediately ceded the place back to his opponent, and then had to change his strategy slightly when Schumacher pitted at the same point as McLaren was expecting him. With Button due in on the following lap, Hamilton had to wait a couple of tours before stopping, and that was enough to keep Schumacher in front.
The battle was eventually resolved on lap 27, apparently when Schumacher missed a gear into the DRS zone at Ascari, but, by that point, it was for fourth rather than third as Button, having caught the duel, despatched both his rivals on lap 16. Taking advantage of Hamilton having to back sharply out of a move at Curva Grande, the 2009 world champion then closed on Schumacher in the second DRS zone and swept around the outside into Ascari to continue his rise from seventh at the restart.
At the same time as Hamilton finally overcame his nemesis, Button was running with Alonso, having closed down to gap to the Ferrari over the space of nine laps. The margin back to the Schumacher/Hamilton scrap was, in turn, nearly eight seconds, highlighting the time that the Briton was losing while bottled up behind the Mercedes. Button appeared to lose the immediate chance to deal with Alonso when making his second and final stop, as the recovering Barrichello pitted at the same time, but entered more slowly than the McLaren. Somehow, any time lost had been erased by the time Alonso had made his stop, with the two rivals back together on track, but with the Briton in a car happier with the harder Pirelli tyres.
It took just a couple of laps for Button to eventually find a way through, the McLaren getting a better exit from the Rettifilio and powering past the Ferrari through Curva Grande. Alonso remained in the battle for another few laps, but Button was eventually able to pull away, ultimately coming home seven seconds ahead.
With the top two cemented barring disaster, attention switched to the fight for the remaining points, with Hamilton's pursuit of Alonso at the top of the bill. As his team-mate had, the Briton inched closer to his former team-mate, but was just unable to make a move stick, despite being able to employ DRS on the final couple of tours. Alonso held firm, and fair, and crossed the line just half a second ahead of the McLaren - to the obvious delight of the tifosi.
Schumacher and Massa were comparatively lonely in fifth and sixth, albeit the last of the unlapped runners, while Jaime Alguersuari took full advantage of a quick Toro Rosso and the chaos at turn one to climb from 18th to eleventh on the opening lap, and then progress to seventh by the flag. The Spaniard ensured that the remarkable run of drivers exiting qualifying in stage one and then scoring points continued for a seventh race, having started the trend back in Canada.
Paul di Resta was forced to take to the cut-through on lap one, but survived the accident and then kept his nose clean for the remaining 53 laps to claim eighth place and the four points that lifts Force India above Sauber, which had a nightmare race with two DNFs. di Resta almost came up short, however, as the charging Bruno Senna crossed the line just 0.8secs behind after making an early pit-stop under the safety car to get off the hard tyres and then gaining places at regular intervals. It was a first top ten appearance for the Brazilian who, after a year at the back with Hispania in 2010, got the chance to join Petrov at Lotus Renault in Belgium a fortnight ago.
The final point was claimed by Buemi, who clearly suffered few ill-effects of bouncing over the back of Rosberg's car at the start and, despite not being to hold Senna off, came home a couple of seconds clear of Pastor Maldonado. Barrichello was next up, with Heikki Kovalainen some way back in 13th, albeit posting his best result of the season and strengthening Team Lotus grip on tenth place in the constructors' series. Timo Glock was the last classified finisher after Virgin team-mate Jerome d'Ambrosio succumbed in the early going, while Ricciardo returned after his own early need for attention, gaining vital race experience despite finishing 14 laps down.
For all the action in the field, however, Vettel remained untroubled, recording his 18th career victory, and Renault power's first since Johnny Herbert's unlikely 1995 triumph for Benetton. The German was tearful on the podium, a mixture of the emotion of becoming a two-time Italian GP winner as well as the team's decision to dedicate the victory to a fallen member of staff, and could be again in a fortnight's time should the result in Singapore go his way.