Fresh from his first MotoGP podium as a Yamaha rider, Andrea Dovizioso returned to the Catalunya circuit on Monday and led the official post-race test.
Dovizioso was the only rider to dip below the 1m 42s mark as he tried a new engine and electronics for his Monster Yamaha Tech 3 machine.
The Italian, now fourth in the championship and the top satellite rider, wrote on Twitter (@AndreaDovizoso):
“Happy for today's work. Tried new electronics and is better for the control when the grip goes down and for life of tyre, but not change on speed.”
The former factory Honda rider then added: “I like Yamaha more and more...”
Just 0.146s behind Dovizioso was factory Yamaha star Ben Spies, who rode for 45 laps (3 more than Dovizioso) working on different engine specs, frame variations and some electronics settings.
Team-mate, world championship leader and Sunday's race winner Jorge Lorenzo set a more sedate pace, clocking the eighth fastest time after being tasked with fixing Yamaha's future focus 'on traction or an increase in power'.
Spaniards Hector Barbera (Pramac) and Alvaro Bautista (Gresini) both posted fast laps at the end of the day to claim a surprise third and fourth.
Repsol Honda riders Dani Pedrosa and Casey Stoner were fifth and sixth - and within 0.38sec of Dovizioso - as they worked on adapting the new specification Bridgestone front tyre to the RCV.
The pair prefer the old spec front, but from Silverstone onwards only the new spec will be available.
Dovizioso's team-mate Cal Crutchlow smashed his M1 when he hit a damp patch on only his second lap of the day, before returning to set the seventh quickest time. Cardion AB's Karel Abraham was another early faller on his way to twelfth.
Behind Lorenzo in ninth was rookie Stefan Bradl. The LCR Honda rider used the morning session to work on front-end feel, then focused on improving traction in the afternoon.