Marc Marquez picked up where he left off during a private COTA test in March by leading the MotoGP field during a slippery Friday morning practice session for the inaugural event in Austin, Texas.
The Repsol Honda rookie, third on his MotoGP race debut in Qatar, led most of the 45-minute session, finishing with an advantage of just 0.253s over world champion Jorge Lorenzo.
However lap times were over five-seconds slower than the best set at the March test.
"It feels like the first day when we were here for testing, the track has very little grip, so this morning I was just finding my rhythm and learning the lines again!” confirmed Marquez. “There's not much more to say! The times were slow but I think this afternoon's free practice will be better.”
Marquez's team-mate Dani Pedrosa was third fastest, but some 1.6s behind the reigning Moto2 champion.
"It was very difficult to try any settings on the bike as the track conditions were not very good, there is no grip,” echoed Pedrosa. “Also, it's quite windy so on the straights the wind is cooling the tyres quite a lot. I hope that the conditions will improve this afternoon with some more sun and bikes on track"