Team Penske teammates Ryan Briscoe and Helio Castroneves weren't far behind, with Briscoe recording the fifth-fastest lap of the day - 1:01.8420 in the No. 6 Team Penske Dallara/Honda - and Castroneves posting the seventh-best lap at 1:01.9364 in the No. 3 Team Penske Dallara/Honda.
Power's effort wasn't surprising, despite his time away from the cockpit. He won at Toronto in th last race held at Exhibition Place in 2007. In his previous street race with Penske Racing, Power won the pole position and finished second in the Grand Prix of Long Beach in April.
"We were reasonably satisfied with third in the Penske Truck Rental car today while trying to find the right combination for qualifying tomorrow," Power said. "I was struggling a bit under braking as I caught slower traffic and also while catching cars exiting the pits, but this should be better tomorrow with fewer cars on track. With rain potentially coming tomorrow, it could make things interesting."
Briscoe, who is tied for second in the IndyCar Series standings, missed about half of the morning practice as the team dealt with some gearbox issues. In the afternoon, Briscoe settled in as he felt more comfortable on the course in his first visit to the Toronto street circuit.
"I've really been learning the track today," said Briscoe. "I think we have a competitive car for Team Penske this weekend. The track is definitely bumpy and it's a challenging, very technical street circuit. I think it's going to be a difficult race for everyone to be consistent, but we still have some time in practice and qualifying to get to where we want to be. We're really excited to be back here racing in Toronto."
Castroneves, who is racing at Toronto for the first time since 2001, had a run-in with the wall late in the second practice session, but the damage was minor.
"The Team Penske car was good today and we had a good lap going there in practice, but unfortunately when I downshifted, the car kept pushing and pushing and it wouldn't turn in and I hit the wall (in turn 5)," Castroneves said. "Fortunately, there isn't too much damage. We still have practice tomorrow and qualifying as well and I think we can be strong there."
The Penske Racing cars return for another morning practice session on Saturday. Qualifying from Toronto is scheduled for 2:05 p.m. ET. The Honda Indy Toronto is set to start at 1 p.m. ET Sunday. It will be televised live by ABC-TV.