Team Penske’s Will Power has gone fastest in the sole Practice session for this weekend’s Iowa IndyCar double-header.

Power headed up an all-Chevrolet top three at the end of the 90-minute session, ahead of Ed Carpenter Racing’s Conor Daly and fellow Penske driver Scott McLaughlin, with Honda’s best being Chip Ganassi Racing’s Alex Palou.

Daly’s personal-best lap, a 173.239mph (278.801km/h)/18.5778s, had him quickest after the initial runs and that was still the case when a Caution was called in the 23rd minute for a track inspection.

In fact, it took until the 70th minute for that marker to be bettered, when Power laid down a 173.285mph (278.875km/h)/18.5729s lap.

Minutes later, McLaughlin, whose only previous visit to Iowa Speedway was a test last month, made it a Penske one-three with a 173.083mph (278.550km/h)/18.5946s effort.

Those laps were followed shortly by a second Caution, ostensibly for another track inspection, although it coincided with a fox running across the 0.875-mile tri-oval.

The green flag flew again with just over 10 minutes remaining, but the top three remained the same for the balance of proceedings.

Palou, however, crept up to fourth on a 172.764mph (278.037km/h)/18.6289s, edging Pato O’Ward to fifth after the McLaren SP driver had gone as quick as a 172.687mph (277.913km/h)/18.6372s.

Rounding out the top 10 were series leader Marcus Ericsson (Ganassi), Josef Newgarden (Penske), Graham Rahal (Rahal Letterman Lanigan Racing), Jimmie Johnson (Ganassi), and last-start winner Scott Dixon (Ganassi).

Notables further back included Felix Rosenqvist (McLaren SP) in 12th, Colton Herta (Andretti Autosport w/ Curb-Agajanian) in 14th, Takuma Sato (Dale Coyne Racing w/ Rick Ware Racing) in 15th, Simon Pagenaud (Meyer Shank Racing) in 17th, Helio Castroneves (MSR) in 19th, and Alexander Rossi (Andretti Autosport) in 20th.

Qualifying is a two-lap format, with drivers’ respective first laps setting the grid for Race 1 of the weekend and second laps for Race 2.

Qualifying gets underway on Sunday morning at 00:30 AEST, and Race 1 at 06:06 AEST, with both of those sessions live and ad-free on Stan Sport.

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Results: Practice