From that point on, the advantage was extended except for when the Ferrari found itself in traffic and, coupled with what appeared to be a long stop for Button, suggested that the Briton had switched onto a two-stop strategy. Where Button had led by a round a second prior to lap nine, he inherited a growing deficit that rose to around 16secs by the time the second round of stops was in full swing.
Those hoping that the BAR driver may still have a trump card to play with one fewer stop to complete were disappointed when Button arrived back at his box for another helping of fuel and rubber - and did so before the race leader.
With the battle for top spot having become strung out as Button appeared to struggle with a poor second stint, attention switched to those in its wake, where Montoya ran solo in third place, ahead of an increasingly frenetic battle for fourth between the two Renaults, Ralf Schumacher and Rubens Barrichello. Jarno Trulli and Fernando Alonso had risen from the bottom half of the top ten through a combination of good starts and interesting tactics, stopping later than their rivals and making up ground.
With the pale blue cars staying out on track, the battle for position switched to the pits where Barrichello and Schumacher Jr stopped in tandem for the second time on lap 28. Both Ferrari and Williams crews did well, with Schumacher just getting out ahead of his rival, maintaining their positions. When Trulli stopped a couple of laps later, however, the Renault crew got him back into the fray between Schumacher and Barrichello, with Alonso dropping to eighth after his second stop.
The numbers were reduced by two in short order as Minardi's Gianmaria Bruni calling it a day when he encountered a sticking brake and Cristiano da Matta slithered off the road shortly after emerging from a drive-thru penalty.
Entering the closing stages, and Schumacher held as commanding a lead as he had enjoyed all afternoon, and could begin to ease back on his pace. Button was equally comfortable in second place, with Montoya gradually slipping back towards the squabbling group behind him, and again stopped ahead of the race leader. An eight-second stop was good enough to get him on his way without a loss of position, but it could not compete with the six-second effort dished up by Ferrari, confirming Schumacher's advantage.
Barrichello and Montoya pitted on the same lap this time around, but there was never any danger of the former catching the latter without a degree of finger trouble creeping into the Williams team's work. One lap later, Schumacher Jr was in, but, again, the German resumed ahead of his Brazilian rival without too much trouble, leaving the attention focused on Renault.
Trulli's stop was quick enough to retake the track ahead of Barrichello, but the real gainer was Alonso, who did not stop until lap 48 and then came out in fifth spot. This allowed the young Spaniard to quickly catch up with Schumacher Jr, and the two came together at Tosa two laps later. This time Schumacher came off worse, spinning down behind Barrichello while Alonso was able to carry on, delayed on slightly, in fourth place. The incident, however, was referred to the stewards for further consideration.
Alonso's pace was unabated and, over the final ten laps, closed remorselessly on Montoya, sensing a podium position. The two crossed the line almost nose-to-tail, but it was the Colombian who prevailed. Behind them, Trulli fended off Barrichello, with an even smaller gap covering Renault and Ferrari at the chequered flag. Ralf was no longer a factor, and only just managed to remain the final unlapped runner, coming home 58secs adrift of his brother.
The final point-scoring spot was filled by..... Kimi Raikkonen, as the luckless Finn saw the end of a grand prix for the first time this season. It had not been an easy ride for the man who was expected to provide Schumacher's closest title challenge this year, and he had to resist a determined pursuit from Giancarlo Fisichella in the closing stages, but he finally opened his account after starting dead last.