Vinales sets pace
Vinales, who started on pole made it count, keeping the lead heading into Turn 1 as third place Quartararo grabbed P2, with Pol Espargaro (Red Bull KTM Factory Racing) dropping back slightly from second on the grid.
Franco Morbidelli (Petronas Yamaha SRT) pounced for P3, with Marquez giving himself work to do after a wobble off the line. But work is exactly what the seven-time champion did, grabbing third from Morbidelli at Turn 8 as the leading trio throughout the weekend found themselves 1-2-3 on Lap 1.
Back at the front, Quartararo had a 0.8sec lead over Marquez, with Vinales slipping to 1.5sec back on Lap 6. The Frenchman's advantage would not stay above half a second for long though as the Repsol Honda began to reel the Petronas Yamaha in; the reigning world champion and the MotoGP rookie locked in a face off.
Vinales then seemed out of range nearly three seconds back, but late race pace has often been a calling card for the number 12.
Rossi in action
Valentino Rossi pressured Morbidelli for fourth, Vinales was at a fairly constant gap, and Quartararo remained nigh on faultless at the front.
There was no sign of the 20-year-old buckling under the pressure, with the gap between the two hovering at two tenths.
Last lap drama
In the final lap, the number 93 was about to strike. Marquez had the run on Quartararo and led into Turn 1, but Quartararo got a good run out of Turn 2 and Turn 3 to bite straight back. Into Turn 4 they went, Quartararo was back in front, but the back straight and Turn 8 provided a golden passing opportunity and Marquez got it stopped into the left-hander - slicing back into the lead.
As the tight left of Turn 14 approached, the Frenchman was right behind the Spaniard. Marquez went defensive and was slow mid-corner, Quartararo tried to cut back...but there was no way through as the Yamaha almost touched the rear wheel of the Honda. Subsequently, Quartararo had to sit up, and that was sadly game over.