Nelson Piquet Jr topped the timesheets in the first practice session in Long Beach for China Racing ahead of Mahindra Racing’s Bruno Senna and Andretti's Scott Speed.
The China Racing driver posted a 59.723s around the seven-turn, 2.1km street circuit to take the top spot before the session was halted six minutes from time following a red flag caused by Daniel Abt hitting the wall on the exit of the first chicane.
Despite briefly stopping on track, Speed – who secured a podium finish on his debut last time out in Miami – claimed third spot ahead of team-mate Jean-Eric Vergne and Abt. Sebastien Buemi (e.dams-Renault), ended the session sixth ahead of Stephane Sarrazin (Venturi) and Sam Bird (Virgin). Lucas di Grassi (ABT) completed the top-10 who were separated by just over half a second.
Championship leader Nico Prost ended 12th with the next 25-minute practice session beginning at 09:25 (local time).
To view the results in full click here.