Jolyon Palmer set the fastest time in GP2 practice at Sepang with a lap of 1:46.514s, with iSport the only team to run on the medium compound tyres during the session.
Despite staying on the hard compound Pirelli tyres for the 30 minute session and suffering a lock-up on a late flying lap, DAMS' Davide Valsecchi still managed to come close to the iSport driver at the top of the timesheets and was just 0.164s slower than Palmer when the chequered flag came out. Carlin's Max Chilton finished fourth ahead of Caterham Racing's Giedo van der Garde.
Valsecchi set an early fastest lap while there were local yellows out in sector 13 following a clash at turn 12 between Lotus GP's Esteban Gutiérrez and Barwa Addax's Johnny Cecotto which left Gutiérrez stuck in the gravel with damaged front right suspension. The accident took place when Cecotto tried to pass a slow Gutiérrez around the outside in the middle of the corner.
Stewards announced they would investigate the clash after the end of practice, while Trident's Stephane Richelmi was also due for a post-session investigation for a separate issue.
Cecotto brought out a second local yellow when he spun in the dying minutes of the session coming out of the penultimate corner, causing many drivers to miss out on a final flying lap while stewards helped push his car back onto the track.
The session stayed dry throughout, although dark clouds gathered overhead towards the end and looked set to give the circuit a wash before F1 Free Practice 2 and GP2 qualifying in the afternoon.
Full practice times