Marc Marquez ended Jorge Lorenzo's run of dominance at Aragon by setting the quickest lap of the weekend so far by just over a tenth of a second in third practice.
The reigning MotoGP champion was quickest out of the blocks, setting what would prove to be the benchmark time early in the session - a 1m47.380s.
That was 0.137s faster than Lorenzo's best Friday time, the Yamaha rider not improving in FP3 as he opted to focus on longer runs, circulating in the mid-1m48s for much of the session.
Lorenzo's best time of the session was a 1m47.775s, putting him behind Dani Pedrosa and Valentino Rossi for the day - although he stayed second in the combined classification.
Pedrosa and Rossi were both late improvers, lapping with 0.283s and 0.312s of pacesetter Marquez respectively in the final five minutes of the session.
Meanwhile, Andrea Iannone hauled himself inside the top five with a final effort of 1m47.786s, which put him half a second clear of top satellite rider Cal Crutchlow (LCR Honda).
Tech 3 Yamaha duo Bradley Smith and Pol Espargaro both failed to improve on their times from Friday, dropping to seventh and eighth in the overall standings, the former suffering a crash at Turn 5 before resuming on his spare bike.
Maverick Vinales and Aleix Espargaro, both on Suzukis, assured themselves of automatic Q2 berths, meaning Ducati's Andrea Dovizioso, as well as Scott Redding's Marc VDS Honda, will have to fight his way through Q1.
Vinales recovered from a low-side crash at Turn 2 to book his Q2 spot, with Jack Miller (LCR Honda) and Loris Baz (Forward Racing) also falling at the same corner, the latter failing to set a time at all.
Practice results (session only):
|16||Mike Di Meglio||Ducati||1'49.464||2.084|
|21||Alex de Angelis||ART/Aprilia||1'50.485||3.105|
|24||Toni Elias||Yamaha Forward||1'51.561||4.181|