Drama at start
There was drama even before lights out at Termas de Rio Hondo, with the conditions hard to judge and the race delayed as the majority of the grid went back into pitlane to switch tyres.
That left Alma Pramac Racing's Miller alone on pole after the Australian didn't need to switch, and the grid lining up a few rows back in order to not all start from pit lane.
Miller was in the lead initially before being hunted down by a group of three: Zarco, Rins and Crutchlow, and they were soon on the scene.
Back at the front, Rins led briefly before an error, and Miller then suffered his own - with Crutchlow able to move through to lead from Zarco and the three able to pull away from Miller.
The drama was far from done, however. On the fight back, Marquez had picked off Andrea Dovizioso (Ducati Team) and honed in on the Movistar Yamaha MotoGP duo of first Rossi and next up Maverick Vinales, until the number 93 made a lunge up the inside of the ‘Doctor' - and misjudged it.
Both running wide and forced to sit up, Marquez was able to stay ahead - but the number 46 went down as he clipped the grass.
Rossi was in sixth place, trying to stick to the rear of the number-25 YZR-M1, when the nine-time world champion's efforts were disrupted when Marquez collided with him in turn 13 on lap 20, causing the Italian to go wide and crash on the slippery wet grass.
Though the Italian Rossi was able to re-join the race, he came no further than a 19th place finish, 52.082s from the front as the incident lit the fuse on the race and the rivalry once again.