Kirkwood topped the 75-minute session around the 11-turn, 1.786-mile Exhibition Place street course with a best lap of 1m00.8075s.
Chip Ganassi Racing’s rookie Marcus Armstrong set the early pace at 1m03.8989s as drivers encountered a track that was bumpier than ever after a brutal winter in the Canadian city.
Sections of the track had been resurfaced since, but the patchwork quality of the asphalt was causing cars to bottom out regularly – especially with the manhole covers positioned under braking at Turn 8 and near the apex of Turn 10. Graham Rahal labelled it: “Ridiculously bumpy, stupid.”
Rahal Letterman Lanigan Racing held a 1-2 after 30 minutes of running, with Jack Harvey heading Christian Lundgaard. Local hero Devlin DeFrancesco spent a turn at the top for Andretti Autosport before his team-mates Colton Herta and Kirkwood, the Long Beach GP winner, took over.
Ganassi’s Scott Dixon hit the front after 40 minutes with 1m02.2594s but was quickly beaten by points-leading team-mate Alex Palou by 0.004s, with a time of 1m02.2554s.
Arrow McLaren’s Alexander Rossi ran later than most and jumped to the top with 1m02.0383s before brushing the wall at the exit of the final corner. Kirkwood re-emerged to beat that with 1m01.8639s, which remained the fastest time set on the primary tyres, with the McLarens of Rossi and Pato O’Ward just about a tenth behind.
Alexander Rossi, Arrow McLaren Chevrolet, Tony Kanaan
Photo by: Richard Dole / Motorsport Images
Teams then switched to the softer alternate rubber, which have green sidewalls this weekend, led by Lundgaard with 1m01.6996s, who was quickly beaten by Palou on 1m01.3233s and then Kirkwood retook P1 with 1m01.1237s.
Herta and then Romain Grosjean made it a brief Andretti 1-2-3, until the McLarens of Rosenqvist (second) and Rossi (fourth but clipped the wall again) mixed it up.
Kirkwood wasn’t to be denied, however, snatching top spot with 40s remaining with 1m00.8075s. Grosjean was 0.05s behind in second, ahead of Rosenqvist, Herta, Scott McLaughlin (Team Penske), Marcus Ericsson (Ganassi), Rossi and O’Ward. Palou slipped to 12th.
Tom Blomqvist got his first taste of an IndyCar race weekend, subbing for the yet-to-be-cleared Simon Pagenaud at Meyer Shank Racing. He finished the session 26th, almost 3s off the pace but ahead of Santino Ferrucci (AJ Foyt Racing).
Second practice starts on Saturday at 10:35am local time.
IndyCar Toronto – FP1 results