Reigning MotoGP World Champion is fastest after FP2, in which Dani Pedrosa finishes in fifth position.
Marc Márquez improved his times by a second and a half from FP1 to FP2.
For the fifth consecutive year, Marc Márquez was the fastest on the first day at the Circuit of the Americas.
The current World Champion set a time of 2:04.061, using the hard front tyre and the soft rear.
Dani Pedrosa clocked a time of 2:04.811, using the soft front and rear tyres.
