Vinales on the move
Cal Crutchlow (LCR Honda Castrol) moved himself into the top 10, Jack Miller (Pramac Racing) and Franco Morbidelli (Petronas Yamaha SRT) took P2 and P3 on the combined times respectively and leader Quartararo had not improved.
So it was instead Vinales who first displaced Marquez from P1, but the Frenchman was on a charge and made his first gains to get up into second and then go top with an even better effort.
Marquez in the mix
That sees him top so far from Sepang winner Vinales and champion Marquez, with Miller in fourth at the end of the day despite a crash - and the Australian was second in FP1.
Morbidelli takes P5, ahead of Alex Rins (Team Suzuki Ecstar). The two-time premier class race winner got the better of rookie teammate Mir in the end, but not by much as the number 36 ends Friday in seventh.
Ducati charge
Aleix Espargaro (Aprilia Racing Team Gresini) impressed in P8, with late times from Andrea Dovizioso (Ducati Team) and Johann Zarco (LCR Honda Idemitsu) seeing them grab a top 10 place in ninth and tenth respectively.
Zarco's temporary team-mate Crutchlow was the man to lose out as he ended the day in 11th.
Rossi crashes
He will be a big name hoping to improve in FP3, and perhaps the biggest name has the same task ahead of him on Saturday: after crashing in FP1 at Turn 4, Valentino Rossi (Monster Energy Yamaha MotoGP) was unfortunately in the gravel again in FP2.
This time it was the fast right-hand Turn 10 that caught ‘The Doctor' out and thankfully the nine-time world champion was okay.
Lorenzo's final Friday
The same couldn't be said for his YZR-M1. He was 14th and will be aiming to leapfrog Michele Pirro (Ducati Team), Danilo Petrucci (Ducati Team) and Crutchlow as a minimum before qualifying.
The retiring Jorge Lorenzo (Repsol Honda Team) ended his final Friday in the sport in 16th, but just 0.012 off Francesco Bagnaia (Pramac Racing) ahead of him. What will Saturday bring?