Fortunately for him, there was already a big margin leading back to fifth, courtesy of Corser, whose strong start from ninth on the grid was flattering to his actual pace. With the Australian backing his rivals up, a large gap opened up between fourth and fifth before Leon Haslam was able to get through.
He was followed by Shane Byrne and Marco Simoncelli – up to seventh having fallen outside the top ten at the start -, as Corser trailed off.
Having already impressed with his pace over a single lap on the unknown RSV-4, Simoncelli was proving to be an adept racer too as he tackled Byrne and then Haslam, the Italian up to fifth and not lapping far off the leaders' lap times. However, it all came to a disappointing conclusion on lap ten when he low-sided out of the race at the Tosa left-hander. The corner had been problematic for a number of riders, with Carlos Checa and Byrne also falling at the same point shortly before.
Back at the front, Biaggi was continuing to hold firm in the lead, but was now under pressure from Fabrizio, who defied Ducati Xerox team orders assumptions by re-taking second from Haga with a similarly opportunistic pass at turn one.
Proceeding to offer some competition for Biaggi, Fabrizio – hampered by a shoulder injury – was very nearly able to capitalise on a mistake for his Roman counterpart out of Tosa, but could do nothing about the Aprilia's sheer speed.
Indeed, with the various undulations, not unlike Brno, apparently favouring the compact Aprilia's renowned top speed, no matter how many times Fabrizio or Haga got alongside Biaggi, they could not out-drag him, particularly up the hill.
Even so, it was Haga's turn again to try and out-fox Biaggi as he swept past Fabrizio on lap eight on the run down to Rivazza.
A very similar pass on lap ten would actually see Haga past Biaggi, only for the home favourite to get the crowd on its feet by fighting back straight away into turn one.
With the leading trio tripping over one another, Spies was beginning to haul himself back into the reckoning. Even so, he was starting to be backed up by Fabrizio, the Italian complaining of a clutch problem to go with his painful shoulder post-race.
Allowing Haga some margin of error as he attempted to find his way around Biaggi, the Japanese rider was staying cool as he sized up his opponent, attempting to unnerve him by getting as close to the rear of the Aprilia as possible.