Andrea Dovizioso moved to the top of the MotoGP title standings at Silverstone, winning the British Grand Prix as reigning world champion Marc Marquez dramatically retired with apparent engine failure.
Marquez held a 16-point lead over Dovizioso ahead of Sunday's race, but the Spaniard's hopes of adding to his tally were dashed as smoke billowed from his Repsol Honda with seven laps remaining.
Valentino Rossi had overtaken pole-sitter Marquez at the first corner and continued to lead the way until lap 18 of 20.
However, Rossi came under pressure in the closing stages and Dovizioso found a way past his fellow Italian to secure his second win in succession and fourth of the season.
The Ducati rider now sits nine points clear of Marquez, with Maverick Vinales a further four back after the latter snatched second from his Movistar Yamaha team-mate late on.
Rossi's third-place finish leaves him 26 points adrift of Dovizioso in fourth.
DOVIZIOSO TIMES HIS CHARGE PERFECTLY
In the first half of the race, Rossi was able to ease clear at the front of the field - opening up a lead of more than a second at one point.
However, the veteran's advantage was gradually reduced and there was a sense of inevitability as Dovizioso shadowed his compatriot after getting the better of Vinales.
Dovizioso made the decisive move on lap 18 and Rossi was also passed by Vinales as he struggled for pace late on.
BANG GOES MARQUEZ'S TITLE LEAD
Although Marquez was hardly enjoying his best race on Sunday, few could have anticipated what would transpire on lap 14.
Seemingly more competitive after a sluggish start, the Spaniard was involved in a fascinating tussle with Dovizioso, Vinales and Cal Crutchlow when his bike suddenly ground to a halt.
Marquez could only watch on thereafter as Dovizioso took full advantage of his rival's misfortune.
IN THE POINTS
1. Andrea Dovizioso (Ducati)
2. Maverick Vinales (Movistar Yamaha) +0.114secs
3. Valentino Rossi (Movistar Yamaha) +0.749s
4. Cal Crutchlow (LCR Honda) +1.679s
5. Jorge Lorenzo (Ducati) +3.508s
6. Johann Zarco (Monster Yamaha Tech 3) +7.001s
7. Dani Pedrosa (Repsol Honda) +10.944s
8. Scott Redding (OCTO Pramac) +13.627s
9. Alex Rins (Suzuki Ecstar) +15.661s
10. Alvaro Bautista (Pull&Bear Aspar Team) +25.279s
11. Pol Espargaro (Red Bull KTM Factory Racing) +30.336s
12. Tito Rabat (EG 0,0 Marc VDS) +31.609s
13. Karel Abraham (Pull&Bear Aspar Team) +31.945s
14. Hector Barbera (Reale Avintia) +33.567s
15. Loris Baz (Reale Avintia) +33.901s
Andrea Dovizioso - 183
Marc Marquez - 174
Maverick Vinales - 170
Valentino Rossi - 157
Dani Pedrosa - 148
Misano hosts round 13 of the season - the San Marino Grand Prix - in a fortnight's time.