Casey Stoner said he feared he would have to retire from the lead of the Italian Grand Prix when his Ducati developed a clutch problem in the closing stages.
The Australian, whose second victory of the year and first since the Qatar season opener moves him back into the points lead, charged to the front after getting up to speed on dry tyres quicker than the rest of the leaders as they rejoined following the mid-race pitstops in the wet-dry event.
He went on to beat the two works Yamahas to the chequered flag, but later revealed that he had been on the brink of pulling out due to the clutch issue.
"I started having problems with the clutch," Stoner said. "We started spinning out going down the main straight, there was no power going through the bike. I thought it was race over - I thought we'd burned the clutch out somehow and we weren't going to finish the race.
"I just tried adjusting it as much as I could, and we got to a point where it started to grab again and go. Then we started having the bike lock up coming into corners because we'd adjusted the clutch too far in. It was really, really difficult to ride.
"But luckily enough we managed to hang on through a few moments and a few saves, and managed to take the win, which we're absolutely stoked about."
Stoner was fast in both the wet early laps and the dry second half of the event, but lost ground temporarily during the changeover period as the track dried. He said he had learned from the frustrations of Le Mans a fortnight ago, where he was quick at first then faded to fifth - half a minute down on winner Jorge Lorenzo - in the dry part of the race.
"To be honest I was looking forward to a dry race, I thought the weather might hold out, because I'm not too keen on the race where we have to swap and change," said Stoner.
"The beginning of the race started out really well - we had a good feeling with the bike and it was working really well. But as soon as a few more dry patches came through, our tyre just destroyed itself completely and there was absolutely no grip.
"I was pushing just to try and lose as little ground as possible so when we did get on the slick tyres I was in with a chance, but at Le Mans it was just impossible to even get on the podium given how much time we'd lost.
"We learned from our problem with the steering damper at Le Mans so we adjusted that before the race here, so from the beginning we had a much better feeling and a much better rhythm, and from the beginning I was able to pass everybody and go to the front."
He added that he was particularly pleased to win at Mugello given his own record at the track, as well as today's result giving Ducati its first Mugello win and ending Valentino Rossi's seven-year run of success at the venue.
"This is the track that I had my first ever pole position at back in 125s," said Stoner. "I've had a lot of up and down results here but I've always enjoyed the track. I've always had a lot of fun here."