Lorenzo Baldassarri took his first Moto2 win in front of a delighted home crowd at Misano as Alex Rins closed the gap on championship leader Johann Zarco to just three points.
But it was another day to forget for Brit Sam Lowes, as his already frustrating weekend ended up in the gravel trap after a scrap for fourth position.
Ajo Motorsport rider Zarco had started from pole, and despite a bit of first corner shuffling – which included Thomas Luthi running off track before rejoining - emerged in front as the opening lap got moving.
Baldassarri, riding a special stars and stripes edition of his Forward Team machine to mark the 9/11 anniversary, slotted into second position with Luthi third.
On Lap Four the Italian decided it was time to make a move on the Frenchman, but third-placed Franco Morbidelli was waiting in the wings to capitalise. As the duo swapped places, Morbidelli took full advantage and moved into the lead.
In the melee that followed, Zarco was the worst affected and dropped back down to fifth, and was then taken by Lowes who was on a charge aboard his Federal Oil Gresini machine.
Up nearer the front, Rins made a pass on Baldassarri for second and a lap later took the lead from Morbidelli. Baldassarri, who was determined not to get left behind, made a pass on Morbidelli moments later to move into second.
As Rins began to eke out a lead up front, Lowes was on the move, scorching past Luthi for fourth on Lap nine. But it all went wrong a few laps later.
With his eyes on a podium he made a move on Morbidelli for third on Lap 12 but ran wide, allowing Morbidelli back through. Not done yet, Lowes made another move a lap later, the pair touching and Idemitsu Honda Team Asia rider Takaaki Nakagami managed to take advantage and sweep past both.
But before Lowes had a chance to make amends, he appeared to hit a bump and crashed out hard, ending his race.
The upset had given Zarco a chance to close up on all of them, and he was soon past Morbidelli and into fourth. From there, very little changed at the front as the race wore on. Zarco did his bit to try and catch Nakagami, as Morbidelli established himself in fifth ahead of Luthi.
But Baldassarri wasn’t done yet, and had slowly began to reel in Rins. By the penultimate lap he was right on his tail, and made a move. Despite running a bit wide he managed to hold on, and led over the line as the final lap began.
Rins was right behind him, and was determined to have a final go for the win. But as he came alongside him in Turn 12, he ran a bit too wide and ended up running off track. Baldassarri was clear to cross the line to take his first win as Rins regrouped and took second with Nakagami holding on for third and Zarco fourth.
“It was unbelievable, I can’t believe it, “ said a delighted Baldassarri. “It was a great race in Italy, my crowd – it was great rhythm, I tried catch him lap after lap, Alex Rins was riding very good but I wanted to the first because I have had a second in Mugello. I pushed to the limit.”
Zarco now leads the championship on 194 points, with Rins closing in on 191.
Britain’s Danny Kent had an early exit from the race when he crashed his number 52 Leopard Racing machine on the eighth lap, having dropped back to 18th position after starting from 15th position.