Miller Motorsports Park lap record holder Joan Lascorz opened up the World Supersport weekend in the United States by claiming the fastest time in first free practice.
The Spaniard, who started from pole position aboard the Motocard Kawasaki last season, was in good form to move to the top of the timesheets in the closing stages of the session.
It was enough to put him a tenth up on title chaser Eugene Laverty on the Parkalgar Honda and Triumph's Jason Di Salvo, the American putting his knowledge of the Utah circuit to good use to go an impressive third fastest.
Championship leader Kenan Sofuoglu was fourth fastest on the Ten Kate Honda, ahead of Lorenzini Kawasaki's Fabien Foret and Michele Pirro, while Massimo Roccoli, Chaz Davies, David Salom and Katsuaki Fujiwara rounded out the top ten.
The three wild-card riders that will participate this weekend, Tyler Odom, Jason Farrell and Melissa Paris, were 14th, 16th and 18th respectively.