Reigning MotoGP champion Marc Marquez set a blistering pace in free practice ahead of the third round of the 2014 championship in Argentina.
The current leader of the rider's championship was over a second faster than Repsol Honda team-mate Dani Pedrosa with a time of one minute 39.313 seconds on the upgraded Autodromo Termas de Rio Hondo.
Pedrosa was the best of the rest as the field were left in Marquez's wake with Spaniard Aleix Espargaro impressing to record the third quickest time on his NGM Forward Honda.
Stefan Bradl and Andrea Dovizioso rounded out the top five but the latter suffered an engine blow-out early in the session and could only get his Ducati within one minute 0.792 seconds of Marquez's effort.
Jorge Lorenzo had set the fastest time in the morning session but could only manage ninth in the second run, with Yamaha team-mate Valentino Rossi a place ahead of him in eighth.
They were bettered by Yamaha Tech3 duo Bradley Smith and Pol Espargaro, who fell in line behind Dovizioso, with Andrea Iannone rounding out the top 10 despite a big accident early in the session.