Chip Ganassi Racing’s Scott Dixon set the pace in opening practice for IndyCar’s return to the Watkins Glen circuit.
The reigning IndyCar champion put in a 1m24.128 to go fastest in the 55-minute session, which was extended by 10 minutes due to a red flag.
The stoppage was caused by a crash for Conor Daly at Turn 6 after hitting water on a kerb from overnight rain.
Sebastien Bourdais finished three tenths behind Dixon in second place, with Will Power and Tony Kanaan next up.
Firestone 600 winner Graham Rahal was fifth, with Penske’s Juan Pablo Montoya and Ed Carpenter Racing’s Josef Newgarden next.
Simon Pagenaud, Helio Castroneves and Indy 500 winner Alexander Rossi rounded out the top 10 in practice one.
Charlie Kimball, Max Chilton, Ryan Hunter-Reay and Takuma Sato were classified in positions 11 to 14, ahead of James Hinchcliffe.
Spencer Pigot, sporting a new livery for the final two races of the 2016 season with branding from Samsung, was 16th.
Rookie RC Enerson, Mikhal Aleshin, Jack Hawksworth, Marco Andretti and Carlos Munoz were next on the timesheets. Daly managed just four laps and finished 22nd.
