Jorge Lorenzo claimed his first MotoGP™ victory since 2016 as championship leader Marc Marquez suffered a rare setback at the Italian Grand Prix.
Reigning champion Marquez had built a 36-point lead at the top of the standings after three consecutive wins, but his attempts to go for a fourth in a row proved costly at Mugello.
Spaniard Lorenzo made his usual strong start, nipping in front of pole-sitter Valentino Rossi to take the lead, and Marquez set off in pursuit of his compatriot.
However, having made his way past Danilo Petrucci and Rossi to sit second, his aggression was to be his undoing when, with 19 laps to go, he went early into Turn 10.
Although the 25-year-old was able to quickly get back onto the track, any hope of another victory had disappeared. He finished up outside the points, crossing the line in 16th place.
Marquez's failure to score sees his advantage over seven-time champion Rossi, who held off the challenge of Andrea Iannone to claim third behind Andrea Dovizioso, cut to 23 points.
Yet no rider could deny Lorenzo from claiming his first victory since joining Ducati, the 31-year-old leading home a one-two for his team as he ended a 23-race drought stretching back to Valencia in November 2016.
Australia's Jack Miller crashed out on Lap 2, bringing his run of eight straight top-10 finishes to an end.
IN THE POINTS
1. Jorge Lorenzo (Ducati)
2. Andrea Dovizioso (Ducati) +6.370 seconds
3. Valentino Rossi (Movistar Yamaha) +6.629
4. Andrea Iannone (Suzuki Ecstar) +7.885
5. Alex Rins (Suzuki Ecstar) +7.907
6. Cal Crutchlow (LCR Honda) +9.120
7. Danilo Petrucci (Alma Pramac) +10.898
8. Maverick Vinales (Movistar Yamaha) +11.060
9. Alvaro Bautista (Angel Nieto) +11.154
10. Johann Zarco (Monster Yamaha Tech 3) +17.644
11. Pol Espargaro (KTM) +20.256
12. Hafizh Syahrin (Monster Yamaha Tech 3) +22.435
13. Tito Rabat (Reale Avintia) +22.464
14. Bradley Smith (KTM) +22.495
15. Franco Morbidelli (EG 0,0 Marc VDS) +26.644
1. Marc Marquez (Repsol Honda) 95
2. Valentino Rossi (Movistar Yamaha) 72
3. Maverick Vinales (Movistar Yamaha) 67
4. Andrea Dovizioso (Ducati) 66
5. Johann Zarco (Monster Yamaha Tech 3) 64
1. Movistar Yamaha 139
2. Repsol Honda 124
3. Alma Pramac Racing 112
4. Ducati 107
5. Suzuki Ecstar 93
A trip to Barcelona for the Catalan Grand Prix, where Lorenzo has won four times previously, is next. Yet Italian riders have prevailed for the past two seasons, with Rossi's success in 2016 followed by a win for countryman Dovizioso last year.