Jorge Lorenzo finished day one of his home Catalan MotoGP on top of the free practice timesheets and 'feeling good' for the weekend ahead.
The Factory Yamaha star, who leads the championship by eight points, had been behind Repsol Honda riders Casey Stoner and Dani Pedrosa in the morning session - then dominated the following 45-minutes of afternoon track time.
The use of softer rear tyres caused a shake-up in the closing stages, but Lorenzo returned to the top after also switching from the harder option.
The 2010 world champion finished 0.207s in front of surprise second place rider Alvaro Bautista (Gresini Honda).
“The feeling is good today, we started this morning two tenths behind Casey, then this afternoon from the beginning we've been in first position,” said Lorenzo. “We tried the hard rear tyre which is very important for this track because it's a real possibility for the race on Sunday.
“We must improve some little details, especially the braking as we are arriving in the corners at a very high speed but generally we are good. This is a special race for me so close to my home, I really want to be fighting for the podium and the victory for the fans who have come to see me.”
Lorenzo and Stoner have won two races each so far this season. Stoner, winner at Catalunya last year, was just tenth in the afternoon after electing not to run the softer slick.
Lorenzo's team-mate Ben Spies also led the afternoon session on his way to sixth.
“I'm happy, it was a good day. We didn't set the world on fire but we got down to some decent times and got comfortable on the bike," he said. "I think we've got some stuff figured out for tomorrow to make the bike quite a bit better.
"I know what I want out of it; we just need a bit of a different set up. The bike is working really good and the team's working well, we just need to make the set up a bit better so I can push it harder.”