Andrea Dovizioso stormed from mid pack to take the top spot late in FP2 Friday afternoon as many riders saved their best for last as worries about Saturday rain turned Friday into a quasi qualifying session. Close on Dovizioso's heels -- so close, in fact, that he practically was inside the Italian's boots -- was Jack Miller at only nine-thousands of a second back. Miller, who briefly held the top spot, had crashed early in the session but remounted to set his fast lap late.
But the two biggest surprises in a session full of them were Spaniards Marc Marquez and Maverick Vinales -- but for very different reasons.
Vinales finished third in the day's final practice after languishing at the rear or middle of the pack for much of the 45-minute session. But with eight minutes to go, Vinales turned up the wick and quickly dropped into the low 1'39s, finally settling into third, one tenth behind Dovizioso.
For reigning world champion Marquez it was a different story. The session's end that proved so fruitful for many riders didn't help Marquez who led much of both Friday practices and who, at times, has looked untouchable at Argentina's Termas de Rio Hondo circuit. With five minutes left in FP2, he began a quick, and eventually permanent slide back down the timesheet as Cal Crutchlow (4th), Miller and Fabio Quartararo, (5th), Valentino Rossi (6th) and Alex Rins (7th) pushed him down the order.
No response came from Marquez who is known for last-lap heroics even in practice. Weather for Saturday's remains uncertain. Franco Morbidelli and Takaaki Nakagami rounded out the top 10. The top 20 riders are within one second of each other.