Marc Marquez held off Andrea Dovizioso to clinch victory at the Grand Prix of Aragon after Jorge Lorenzo crashed out for the second successive race.
Spaniard Marquez triumphed on home soil for a third successive year, though it was far from straightforward for the world championship leader on Sunday.
His battle with Dovizioso ebbed and flowed throughout after polesitter Lorenzo's early exit, the Ducati rider failing to make it beyond the first corner as he flipped over the front of his bike.
Marquez had initially squeezed into the lead, ahead of compatriot Lorenzo, who suffered a dislocated toe on his right foot, but Dovizioso darted to the head of the field by the end of the opening lap.
The Italian held sway for the majority of the race before the duo began exchanging first place, Marquez – who jumped onto the barriers to salute the crowd during his celebrations – crucially assuming control on Lap 21 before moving clear in the closing stages.
Andrea Iannone secured the final place on the podium ahead of Suzuki Ecstar team-mate Alex Rins, with Dani Pedrosa and Aleix Espargaro in fifth and sixth respectively.
Danilo Petrucci was seventh ahead of Valentino Rossi, the Italian making a late move to pass Jack Miller, with Maverick Vinales rounding out the top 10.
Marquez has now won six times this season, though this success ends a four-race drought that stretches back to the German Grand Prix at Sachsenring in July.
He leads the overall standings by 72 points from Dovizioso with five races to go, making it just a matter of when, not if, he is crowned champion again.
IN THE POINTS
- Marc Marquez (Repsol Honda)
- Andrea Dovizioso (Ducati) +0.648 seconds
- Andrea Iannone (Suzuki Ecstar) +1.259
- Alex Rins (Suzuki Ecstar) +2.638
- Dani Pedrosa (Repsol Honda) +5.274
- Aleix Espargaro (Aprilia Gresini) +9.396
- Danilo Petrucci (Pramac Racing Ducati) +14.285
- Valentino Rossi (Movistar Yamaha) +15.199
- Jack Miller (Pramac Racing Ducati) +16.375
- Maverick Vinales (Movistar Yamaha) +22.457
- Franco Morbidelli (Marc VDS) +27.025
- Takaaki Nakagami (LCR Honda) +27.957
- Bradley Smith (KTM) +28.821
- Johann Zarco (Monster Yamaha) +32.345
- Karel Abraham (Angel Nieto) +37.639
- Marc Marquez (Repsol Honda) 246
- Andrea Dovizioso (Ducati) 174
- Valentino Rossi (Movistar Yamaha) 159
- Jorge Lorenzo (Ducati) 130
- Maverick Vinales (Movistar Yamaha) 130
- Repsol Honda 333
- Ducati 305
- Movistar Yamaha 289
- Suzuki Ecstar 200
- Alma Pramac Racing 187