Lorenzo in front as MotoGP 2012 begins

Jorge Lorenzo began 2012 MotoGP testing on top of the timesheets at Sepang on Tuesday.

The 2010 world champion was riding for the first time since losing the tip of his left finger during warm-up for the Australian Grand Prix on October 16.

That injury also ruled the Spaniard out of November's post-race, meaning Tuesday marked his first 1000cc laps since Misano in early September.

Lorenzo finished the day with a best time of 2m 1.657s, which put him 0.346sec clear of Repsol Honda's Dani Pedrosa. Tech 3's Cal Crutchlow was third (+0.564s).

"It felt better than ever to be back on a MotoGP bike," smiled Lorenzo, who won three races on his way to second in last year's championship.

"Normally it's difficult for me to recover the pace and feeling after the winter break, but today I've been fast from the beginning and I think we have a lot of potential for the future.

"The bike didn't feel so different [to Misano]. I'm happy, but we have a lot of possibilities to improve. With the 800 we arrived very close to the limit, now we have a lot of possibilities. But we need to work in a lot of areas."

Lorenzo's priority is now to make maximum use of the power available, and he also spoke about the difference in riding the 1000cc bike compared with the previous generation of 800cc machines.

"You must [square off] the slow corners and need to be a little bit less precise," he sid. "The bike is much more powerful, so if you make a mistake you have enough power to recover the time on the exit. With the 800 you cannot make any mistakes."

Lorenzo, who didn't race during the previous 990cc era, insisted that adapting to the bigger capacity hadn't been a problem.

"It was easy for me to understand how to go quickly with this bike. I didn't need to spend a lot of time thinking about how I can adapt my style to this bike. I can create a different style lap by lap," he said.

In terms of the latest Bridgestone tyres, Lorenzo gave the following assessment:

"It is much faster to warm-up the new tyres and you can slow down, then speed up again and the tyre stays good," he said. "The other side is that it seems all the riders have this vibration [chatter]."

Lorenzo's added that his finger injury certainly didn't slow him down - perhaps the opposite.

"The finger is shorter and lighter - that's why I went fast today!" he joked. "No the finger's ok, I can still touch the clutch with all the fingers so no problem."

Lorenzo's team-mate Ben Spies was fourth fastest (+0.577s) with a happy Valentino Rossi fifth on the new Ducati GP12 (+0.735s)

Testing at Sepang continues on Wednesday.