MotoGP championship leader Maverick Vinales continued to set the pace in practice for the Argentinian Grand Prix, beating Marc Marquez by three tenths in Friday's second session.
Honda rider Marquez set the early pace with a 1m40.670s set using a medium front and a hard rear tyre, which stood as the benchmark until around the halfway mark of the 45 minutes.
Aspar rider Alvaro Bautista briefly occupied the top spot when he logged a 1m40.386s aboard his 2016-spec Ducati, before becoming first to improve on Vinales' Friday morning benchmark with a 1m40.290s.
Having switched to hard tyres front and rear, Marquez soon ousted Bautista with a 1m40.246s.
That remained the time to beat heading into the final minutes, when the threat of rain on Saturday prompted the majority of riders to fit new tyres to try to get into the top 10 and potentially avoid a Q1 appearance.
LCR Honda's Cal Crutchlow was first to beat Marquez, followed almost instantly by Karel Abraham's 2015-spec Aspar Ducati, before Marquez reclaimed top spot on a 1m39.778s with a medium front and soft rear.
Vinales saved his best for the very end, posting a 1m39.477s with the same tyre combination to beat Marquez by a 0.301 seconds.
Abraham and Bautista finished third and fourth, followed by Danilo Petrucci's 2017 Pramac Ducati - all within half a second of Vinales - while Loris Baz made it four satellite Ducatis in the top six another two tenths back.
Crutchlow ended up being pushed down to seventh, ahead of Jonas Folger on the best of the Tech3 Yamahas, Aleix Espargaro's Aprilia and Andrea Iannone's Suzuki.
Several big names missed out on a place in the top 10, and could have to tackle Q1 on Saturday if forecast rain affects third practice.
Dani Pedrosa was 13th on his Honda, having suffered a low-speed crash at Turn 13 towards the end of his second run, one spot ahead of the best of the factory Ducatis, Andrea Dovizioso.
Valentino Rossi languished in 16th, 1.054s off the pace of Yamaha team-mate Vinales, while Jorge Lorenzo was a further two places further back on his Ducati.
KTM's Bradley Smith was the only other rider to fall in the session, in a high-speed off at Turn 1, and he finished 22nd, one place behind team-mate Pol Espargaro.
PRACTICE TWO TIMES: