Tech 3 rider Iker Lecuona – whose MotoGP future beyond 2021 looks in doubt – set the initial pace on his KTM with a 1m40.860s, which world champion Joan Mir on the Suzuki immediately bettered to a 1m40.342s.
Having ended FP1 third fastest, Pol Espargaro picked up where he left off at the start of FP2 and edged ahead of Mir with a 1m40.146s on the factory Honda.
Teammate Marc Marquez took a brief trip to the top of the standings with a 1m30.120s, before world championship leader Fabio Quartararo took over with a 1m40.006s 10 minutes into the session.
Moments later his Yamaha counterpart Morbidelli – working with the hard rear tyre – went sub 1m40s for the first time on Friday with a 1m39.909s on his Petronas SRT-run ‘A-spec’ M1.
Morbidelli’s time went unchallenged until the closing stages as a period of race preparation halted any major timesheet changes.
The SRT rider’s lap was finally toppled with just over a minute remaining when Brad Binder – who has secured his KTM future through to the end of 2024 – moved clear with a 1m39.662s.
Binder was soon pipped by Zarco with a 1m39.446s, before Morbidelli re-established himself at the head of the pack with a 1m39.256s.
But it wouldn’t be enough to end the session fastest, as Zarco found 0.021s on his final lap to top with a 1m39.235s.
Trailing Zarco and Morbidelli was Quartararo on the works team Yamaha, with Binder fourth at the chequered flag ahead of Ducati factory team rider Francesco Bagnaia.
Maverick Vinales completed the top six on his factory Yamaha ahead of the works Ducati of Jack Miller and an impressive Avintia rookie Enea Bastianini on a two-year-old Desmosedici.
FP1 pacesetter Aleix Espargaro was ninth on the Aprilia ahead of the leading Honda of Pol Espargaro in 10th.
Marc Marquez slid down to 15th in the order behind KTM’s Miguel Oliveira, who ran as high as third in the closing stages.
Mir flew under the radar on the sole Suzuki this weekend in 16th, while Valentino Rossi’s struggles continued on his SRT Yamaha as he ended up 1.6s off the pace in 19th ahead of only Aprilia rookie Lorenzo Savadori and the returning Jorge Martin on the Pramac Ducati.
While several riders ran off track at the revamped Turn 10 left-hander, Luca Marini on the Avintia Ducati was the only faller in the session at Turn 4.