How it unfolded
Rossi had won three straight premier-class titles with Honda from 2001 to 2003, then switched in 2003 to a Yamaha M1 that had not won a single race that year. The move itself was made to prove that the rider, not the machine, produces the result, and the proof arrived immediately, at the season-opening round at Welkom. Rossi took pole position, and in the race fought Honda's Max Biaggi all the way to the final lap. The two swapped positions corner after corner, and Rossi crossed the line 0.210 seconds ahead. On the slowdown lap he stopped the bike, sat down beside the track and stayed there for a long time. The win made Rossi the first rider to win consecutive premier-class races on machinery from two different manufacturers. He went on to win nine races that season for Yamaha and took the championship, then defended the title in 2005 as well.
Why it still matters
This race remains the reference case in the debate over the relative importance of rider and machine in modern MotoGP. The symbolism of winning first time out after a transfer was so strong that every major move since has been measured against it, including the same standard applied when Marc Marquez left Honda in 2024.