Petrucci earned victory with a time of 41 minutes and 33.8 seconds, only 0.043s ahead of Spain's Marc Márquez (Repsol Honda), while Italy's Andrea Dovizioso (Ducati) completed the podium 0.338s off the pace, reports Efe news.
Márquez is still the MotoGP World Champion with 12 points ahead of Dovizioso and 27 ahead of Alex Rins of Spain, who finished fourth at the Mugello Circuit. From pole position, Márquez maintained his lead with the Ducati duo nipping at his heels, but Rins (Suzuki) attacked in the fourth lap.
At that point, Italy's Valentino Rossi (Yamaha YZR M 1) and Spaniard Jorge Lorenzo (Repsol Honda RC 213 V) were away from the fight for the first positions.
The Italian had a bad day in the office; first, he made a mistake and went off the road and shortly after coming back in the last position, he hit the ground in the eighth lap and subsequently had to retire.
The race, however, was anything but secured for Márquez, who was overtaken by Danilo Petrucci in the fifth lap and then in the following lap Ducati's Dovizioso and Australia's Jack Miller followed in Petrucci's footsteps and even Rins momentarily leapfrogged Márquez.
With Ducati's duo in the lead, Márquez engaged in a fierce fight with Miller to regain the third spot and close the gap with Petrucci and Dovizioso. While Márquez emerged victorious from the fight for the third spot, the efforts of Rins, who was following his countryman to take the lead paid off in the tenth lap.
In the same lap, however, Ducati riders and Márquez overtook him, but he was not ready to give up just yet and fought back to surpass Márquez, although the Ducati duo didn't give him an opportunity.
Petrucci, Márquez, Dovizioso and Rins then competed for the first spot, with Dovizioso taking the lead in the 20th lap, but his teammate hit back and grabbed the lead.
The race kept the best to last, in the very last lap, when Márquez overtook both riders, who managed to find a way past Márquez through the inside racing line at San Donato.
In a risky manoeuvre both Dovizioso and Petrucci, entered almost without a place, forcing Dovizioso to lift the bike and literally touch Márquez's bike, which ended in front of him and that relegated him to third.
( With inputs from IANS )