Andrea Dovizioso posted a lap of 2m04.495s, while Cal Crutchlow did it in 2m04.981s.
Jorge Lorenzo took seventh to secure a spot in tomorrow’s second qualifying session within the top ten riders.
Cal Crutchlow ends day in twelfth place after a crash.
Aleix Espargaro continued his impressive form from the Qatar pre-season test.
Open class rider improves on best time while factory teams continue to flounder
The newly named Movistar Yamaha MotoGP riders were out feeling their way on the night track for the first time this year.
At the end of the session, the two Ducati Team riders had recorded thirteenth and fourteenth quickest times.
First free practice session throws up a lot of surprises at the front
The riders of the Pramac Racing team after the hard work done in the three pre-season testing got back on the track for the first practice session of the year.
Spaniard routs first test of year topping the timesheets on all three days
Bradley Smith also enjoyed a magnificent start to the final round of 2013, the British rider storming to the fourth best time this morning.
Andrea Dovizioso and Nicky Hayden completed the first two free-practice sessions for the GP de la Comunitat Valenciana.
Yonny Hernandez still suffering from a fracture of the little finger on his right hand, injured during the recent overseas tripleheader.
Day 1 cancelled at Motegi
Andrea Iannone ended FP2 just 0.183 seconds away from Nicky Hayden and 0.038 seconds from Andrea Dovizioso, confirming the 11th place.
Jorge Lorenzo completed the first day of free practice as the fastest rider.
Despite the wind, Ducati drivers Nicky Hayden and Andrea Dovizioso posted their times of 1:30.609 and 1:30.754 respectively.
Jorge Lorenzo posted a lap of 1’28.961, while Marc Marquez set only a time of 1'29.255 at Phillip Island
Both Ducati Team riders hope to reduce their gaps to the leaders.
Dani Pedrosa’s time was just two-tenths of a second off the qualifying lap record, the Spaniard topping the opening day ahead of teammate Marc Marquez.
There are still some small changes to be made to the Desmosedici GP13 to increase Yonny Hernandez's confidence for qualifying tomorrow.
Andrea Iannone concluded this first day of the challenging Malaysian Grand Prix in 12th position.
Cal Crutchlow setting the third fastest time on the opening day of practice at the physically demanding Sepang International Circuit.
Nine-time world champion Valentino Rossi made solid improvements over the two practice sessions to wrap up the day in fourth in the combined times.
A small problem suffered at the beginning of FP2, prevented Andrea Iannone from taking full advantage of the session.
Yonny Hernandez finished today’s two free-practice sessions with a best time of 1:51.345.
A lap of 1.50.575 in this morning’s FP1 put Crutchlow in seventh position, but a big improvement to a 1.49.840 this afternoon elevated the British rider into the top six.