Spaniard Maverick Vinales on a Yamaha won the Emilia-Romagna MotoGP on Sunday to move up to within one point of the championship lead.
Joan Mir was second on a Suzuki and another Spaniard Pol Espargaro (KTM) promoted a place to third after Frenchman Fabio Quartararo of the Yamaha-SRT satellite team crossed the line behind Mir but was penalised for straying off the track.
South Africa's Brad Binder crashed out of the race while in third place after he qualified sixth.
Andrea Dovizioso finished eighth to cling to the championship lead, one point ahead of Quartararo and Vinales.
Vinales started from pole but soon lost the lead to Francesco Bagnaia.
The young Italian led by a second and a half at one stage and was still on course for a first victory for himself and Ducati-Pramac when he leant a bit too far into a corner with seven laps to go and slid off.
Vinales grabbed his chance to become the sixth winner in seven MotoGP races this season.
"After he made the mistake I tried not to make a mistake and take the points," he said.
"We had prepared really well, I was very fast, I preserved my tyres well at the start and I was able to attack when I had to", said Vinales. "We have a big potential for the rest of the season."
Vinales was able to defend the lead comfortably, finishing more than four seconds clear, because Espargaro and Quartararo had tyre troubles which allowed Mir to pass both.
"I am really tired, because I had to give everything today, at each lap," said Mir. "At the end, I saw that I could see a highway to the podium."
Espargaro said that after racing on medium tyres the week before on the same track he had opted for softs because "I wanted to enjoy my race" adding that he expected problems near the end.
"It paid off, thanks also to the penalty of Fabio."
Quartararo, battling Espargaro strayed onto the green out-of-bounds paint several times, and having a warning on his dashboard received a three-second penalty.
Furious, he returned to his pit without making any comments.
The big disappointment of the day at the Italian track was local hero Valentino Rossi who crashed at the beginning of the race and retired.