Phillip Island - Aleix Espargaro pipped world championship leader Marc Marquez to set the fastest time in Friday's practice ahead of this weekend's Australian MotoGP at Phillip Island.
The Spanish Aprilia rider posted a quickest lap of one minute 29.225 seconds in second free practice on a dry track ahead of Sunday's race.
Espargaro's time, set on the fifth lap of his afternoon session, prevailed by just 0.005secs over Marquez, who almost bettered the time on his penultimate lap.
"It is just the first day, but we are clearly doing a great job," Espargaro said.
"We can improve on pace. The RS-GP (bike) still doesn't turn the way I would like it to and I am lacking a bit of feeling on the front.
"Finding a good feeling for the race will be fundamental."
Marquez, who leads the world championship by 11 points with three races left, clocked 1:29.230 following his chart-topping 1:29.602 in the morning session.
"I think for tomorrow we can try and further improve the set-up, especially the stability of the bike in the fast corners," Marquez said.
"There are a few places where we could be quicker if we can manage to take another step in that area."
Championship challenger Andrea Dovizioso was third quickest overall, finishing just 0.097secs behind Espargaro.
"We have to work to improve a few aspects, because in any case Marquez was also very quick and there are other riders who have a good pace," Dovizioso said.
"Let's see what sort of conditions we will encounter tomorrow, but for sure this was a positive first day for me."
Ducati's Dovizioso downed Marquez on the final lap to win last weekend's rain-soaked Japanese GP and is second in the world championship.
Briton Cal Crutchlow, the winner of last year's Australian race, was fourth fastest on a Honda, only 0.104secs down on the leader's time.
Spain's Maverick Vinales was fifth fastest despite coming off his Yamaha early in afternoon practice.
"The day overall has been really good," Vinales said. "Before the crash I was already coming up with red-helmet (quickest) times in many sectors, but I was trying so hard I pushed the bike over the limit.
"We still have to improve, but the crash was, for sure, my mistake."
Australian Jack Miller, in his first MotoGP event back since breaking a leg during training, was sixth ahead of Suzuki's Andrea Iannone.
Six-time premier class Phillip Island winner, Valentino Rossi, trailed in 12th place overall on his Yamaha, some 0.752secs behind Espargaro's time.
"We have a lot to do, also the tyre choice front and rear is still open, so I hope for good conditions tomorrow," Rossi said.
The weather on the opening day was sunny, but the forecast for Saturday is for cooler temperatures and possible showers.
Australian Grand Prix combined first and second free practice times on Friday:
1. Aleix Espargaro (ESP/Aprilia) 1:29.225, 2. Marc Marquez (ESP/Honda) at 0.005, 3. Andrea Dovizioso (ITA/Ducati) 0.097, 4. Cal Crutchlow (GBR/Honda) 0.104, 5. Maverick Vinales (ESP/Yamaha) 0.198, 6. Jack Miller (AUS/Honda) 0.241, 7. Andrea Iannone (ITA/Suzuki) 0.379, 8. Johann Zarco (FRA/Yamaha) 0.442, 9. Dani Pedrosa (ESP/Honda) 0.477, 10. Pol Espargaro (ESP/KTM) 0.535, 11. Jorge Lorenzo (ESP/Ducati) 0.595, 12. Valentino Rossi (ITA/Yamaha) 0.752