TORONTO - Ryan Hunter-Reay overcame stifling temperatures and a bumpy street course to post the fastest practice lap at the Honda Indy Toronto on Friday, successfully navigating hazards which ensnared a handful of his rivals.

The 29-year-old Floridian, who said his mother was raised in Hamilton, finished a lap in one minute 2.1433 seconds. He finished ahead of Justin Wilson (1:02.1839) and Helio Castroneves (1:02.2550).

"It was definitely a physical, hot one out there today," Hunter-Reay said. "It's going to be a tough race weekend."

The teams return to the course for another practice session on Saturday morning, a couple of hours before qualifying for Sunday's race (TSN2, 12:30 p.m. ET).

Both the morning and the afternoon sessions featured drivers making unwanted contact with the temporary walls around the 1.75-mile course. Clean-up crews were at their busiest in the morning, after a multi-car collision that left one vehicle too damaged to continue.

Takuma Sato spun out at Turn 6 after contact from Scott Dixon, who was then rear-ended by Bertrand Baguette. The first two cars were re-started, but Baguette's was not.

"In Toronto, like any street circuit, the margin for error is very small," Hunter-Reay said. "It's such a fine line, the entire time. It's so easy, with the bumps, to lock a right front and get into the wall."

The collision was the second yellow flag for Sato in the session.

"It was a tough day," Sato said. "The circuit is extremely bumpy and slippery, especially on the concrete patches, which made it very difficult to predict the setup of the car."

Toronto's Paul Tracy made contact with the wall in the second session, and finished with the second-slowest time of the day. Alex Tagliani of Lachenaie, Que., had a better day, posting the sixth-best time -- one of 13 drivers separated by less than a second.

"When you roll off the truck and the car feels good, and you're in the ballpark and you're fighting up in the top five, I think you put yourself in the position where you can have a good result in the race," Tagliani said. "You still can't count the chickens before they've hatched. You really have to continue to work."

"It's not the smoothest track that we go on," said Wilson, the second-fastest driver on the track. "And I think that adds character to the place. You have to deal with the circumstances and try to make the car work."

Toronto's James Hinchcliffe posted the fastest run in the Firestone Indy Lights series with a lap of 1:06.8212.

"The concrete patches just have no grip," Hinchcliffe said. "I was pretty shocked with how little grip there is."

The course will be upgraded for the event next year with a $770,000 investment grant from the federal government. In a release issued Friday, Kevin Savoree, co-owner of Green Savoree Promotions - the company which owns the Honda Indy Toronto -- said the upgrades focus on the barriers and fences.

"Most of the barrier and fence here is 24 years old," Green said in the release.

The 85-lap race is the first of two Canadian events this month. The series travels to Edmonton next weekend.

"Street courses are a little notorious for being really hard to pass, and being a lot of follow-the-leader," IndyCar star Danica Patrick said. "But I was really impressed last year, seeing just how we were able to get runs down the back straight and make things happen."