MotoGP rookie Marc Marquez continued his unbeaten run at the Circuit of the Americas by dominating the first ever grand prix track session in Austin, Texas.
Quickest during all three days of a private test last month, Marquez moved to the top after seven minutes of FP1 and was over two-seconds clear by the midway point.
Riding in bright and sunny, but cool and slippery conditions, lap times continued to tumble.
Marquez - who claimed a fighting third place on his MotoGP debut in Qatar - remained ahead. However his advantage over Yamaha's reigning world champion and Qatar winner Jorge Lorenzo
was cut to just 0.253s by the conclusion of the 45-minutes.
But there is plenty more to come. Marquez's best lap was a 2m 8.756s, compared with a 2m 3.281s on the third and final day of testing.
Dani Pedrosa - Marquez's Repsol Honda team-mate - was over 1.6s behind the reigning Moto2 champion, in third place this morning.
Ducati riders Andrea Dovizioso
and Nicky Hayden
were not among the 'favoured five' that could afford the private test, and thus performed admirably with fourth and fifth places, albeit two-seconds from Marquez.
Kentuckian Hayden, like home-state heroes Ben Spies and Colin Edwards, had ridden the circuit on a road bike. Dovizioso - the quickest Ducati throughout the Losail weekend - was starting from zero.
Lorenzo's team-mate Valentino Rossi
was a surprising low sixth place, given his test attendance. However LCR Honda's Stefan Bradl - the fifth full-time rider with prior COTA MotoGP knowledge - also proved it was no guarantee of FP1 form with ninth.
Although unable to test, the Monster Yamaha Tech 3 and Gresini Honda riders should at least have benefited from gear ratio and other basic set-up data passed on by the factory teams.