Trulli and Webber began the meaningful pit-stops on lap 22, the Australian having seen Sato sweep past for fourth at Villeneuve and almost lose two more places as the chasing Wurz and, fittingly, Villeneuve looked to capitalise on his ensuing moment. Sato and Villeneuve joined Alonso in the pits next time around, the Spaniard losing the lead to Button, but knowing that he would regain the advantage when the Briton stopped next time around.
Whilst cars came and went out front, however, Schumacher was quietly biding his time, working his way through the pack. When Barrichello's car quit, the German was up to tenth, but still struggling to pass his brother's Toyota, but Ferrari knew that it had an ace up its sleeve, as the world champion kept pressing relentlessly on.
His first fastest lap coincided with Button's pit-stop, but merely preceded a string of lightning tours that began to eat in to the leaders' advantage. By staying out three laps longer than Button, and four more than Alonso, Schumacher elevated himself to third place, and had enough of a gap over those already having pitted to be able to hold the position as he returned to the track.
At half distance, Alonso had been restored to the front, with Button his chief pursuer, but Schumacher was now ahead of Wurz, Sato, Trulli and Villeneuve, the midfield pack having relegated both Williams to the role of points hopefuls rather than certainties. Webber and Heidfeld remained in front of Ralf Schumacher, with debutant Vitantonio Liuzzi making a steady, if rather anonymous, first appearance, albeit ahead of the duelling Coulthard and Massa.
Out front, however, battle was now joined, with Schumacher's pace hardly being dimmed by his increased fuel load. The German consistently lapped a full second quicker than either of the men ahead of him, taking visible chunks out of Button's immediate advantage between laps 30 and 40.
When Alonso pitted for the second and final time a lap later, Button was already engaged in defensive mode, the world champion right on his tail. The scrap briefly became that for the lead - not just because Alonso was receiving his top-up, but also because Schumacher was intent on making short work of passing his closest rival of twelve months ago.
Ironically, it was the team that Button could have been driving for this year that contributed to him losing the advantage. Webber and Heidfeld found themselves together on the road and, in shades of Malaysia, got closer than either they or the team management would have wanted. The moment caused Button to think for a split-second, and that was all that Schumacher needed, boxing the Briton in behind Webber and forcing his way through at Variante Alta. Once in front, the Ferrari pulled away with ease.
Schumacher's race was now with himself to see if he could open out enough of a gap to hold the lead when he emerged from the pits. When he was behind Button, Ferrari prepared to call him in but, once the F2005 had moved ahead, the crew returned to the garage and let their champion do his job. Button pitted from second on lap 48, Schumacher from the lead two tours later - fully seven laps further than Alonso had managed.
As it turned out, it wasn't quite enough for the German, who left pit-lane to see the pale blue and yellow form of Alonso's Renault just ahead of him. Closing the gap wasn't the problem, but passing the determined points leader proved to be a tougher assignment. With little of note going on behind, the battle for victory became all-absorbing, with the tifosi on its feet, anticipating a return to form for its beloved Scuderia.
Schumacher took his first look heading into Tosa with eight laps to go, a move that could have been completed at any point up to Acqua Minerale. Alonso, however, had one key advantage and, despite driving defensively, knew that the superior torque of the R25 would help him keep ahead on the exit of corners. The Renault looked marginally better across the top of the circuit, but Tosa, Piratella and Rivazza all provide potential passing places for Schumacher, if he could get close enough.