When the red lights went out to signal the start of 27 unpredictable laps, it was Biaggi who dived inside the Ducatis into turn one, but the Roman ran wide allowing Bayliss to lead his home GP from Gibernau, Capirossi, Melandri, Biaggi, Hayden, Rossi, Ukawa and Checa. Biaggi would make a mistake later in the lap and drop to the back of the pack.
Meanwhile, Gibernau would blast past Bayliss out of the final turn to lead into lap two, while Melandri was also charging – dropping Bayliss a further place soon after, then leading his first ever MotoGP race when he nipped inside Gibernau just half a lap later at Haysheds.
At that stage, Rossi was battling his team-mate Hayden for fifth, the pair passing and re-passing each other as Nicky refused to let his team leader escape.
Lap 3 and Aussie hopes ended when Bayliss crashed out after touching a white line under braking for the Honda hairpin - while running side-by-side on the outside of Melandri; the Aussie hit the ground hard and was thrown like a rag doll through the grass and mud before lying motionless and requiring medical attention. He would later be stretchered away after regaining consciousness and was declared more or less fit after being checked at the medical centre.
While Bayliss was attended to, his accident had far reaching consequences when Rossi passed Melandri under waved yellow flags at the same turn one lap later - in a repeat of the incident that cost him victory at Donington - what would happen this time...?
Meanwhile, by lap 6 Rossi was now leading the field, with battling rookies Melandri and Hayden fighting over second, while Gibernau, Ukawa and Capirossi watched the thrilling action ahead. Hayden would be caught out on lap 8 when he ran wide while trying to retake second from Melandri, dropping him to sixth behind Capirossi, Ukawa, Gibernau, Melandri and race leader Rossi.
Rossi would receive a 10secs penalty on lap 11 of 27 for his earlier yellow flag infringement, at which time he held a 3.5secs lead – meaning he now needed to ride much harder than he'd ever imagined to take victory. Meanwhile, Melandri, Gibernau, Capirossi, Hayden, Ukawa and Checa (separated by just 1.5secs and passing each other continuously) were now potentially locked in a battle for race victory.
But Melandri's hard fighting day would come to an end when he was kicked from his Fortuna Yamaha while chasing new second placed man (or race leader if you subtract Rossi's penalty) Capirossi on lap 14. The incident allowed the Ducati rider to pull a lead on Gibernau, Hayden, Ukawa and Checa as his team tried to inform him of Rossi's penalty - and that he could win his and Ducati's second victory of the season.
However, Rossi was lapping around 0.6secs a lap quicker than countryman Loris to extend his advantage to 6secs with 9laps to go – if he kept that pace up he'd win the race. Over the following laps the #46 would keep punching out mid 1min 31secs laps to extend his lead to 7secs, then 7.5secs, then 8.8secs, then 9.9secs, before finally taking the 'lead' back on lap 23, then continuing to pull away right to the chequered flag!
Checa ran wide later on lap 23 - leaving Gibernau, Ukawa and Hayden to fight for the final podium spot. The Spaniard rejoined in eighth, behind the fellow Yamahas of Jacque and Nakano, and ahead of Suzuki's Kenny Roberts.