The Team Penske driver topped the 22-car field for the NTT IndyCar Series event on the 11-turn, 1.786-mile temporary street circuit with a lap of 59.8708 seconds in the No. 22 DXC Technology Chevrolet. The Frenchman's lap was 0.06 of a second faster than Swedish rookie Felix Rosenqvist who was the top Honda-powered driver on the opening day of practice.
Several drivers struggled for grip in Turn 11, where a patch in the asphalt creates a tricky surface change. Alexander Rossi and Marcus Ericsson grazed the outside wall there in Friday's second practice; Takuma Sato hit the concrete barrier harder. Will Power, Josef Newgarden and Sato slid through that corner in the morning practice, forcing a stoppage in the action. Only Sato's afternoon impact caused noteworthy right-side damage.
Rossi had left-side damage after glancing off the wall in Turn 9. His car came to a stop on the front straightaway. Ericsson hit with the right side in Turn 5.
Rossi's explanation: Drivers need to experiment with driving lines during practice, where there are no points distributed.
"You wouldn't want to do that in qualifying," he said.
Sebastien Bourdais was third overall, the only other driver posting a lap quicker than 1 minute.
A third NTT IndyCar Series practice will be held Saturday at 10:20 a.m. ET ahead of NTT P1 Award qualifying. The 85-lap Honda Indy Toronto will be held Sunday at 3 p.m. ET on NBCSN and the Advance Auto Parts INDYCAR Radio Network. Follow timing and scoring information at racecontrol.indycar.com.