Graham Rahal has topped a final IndyCar practice session at Gateway Motorsports Park which was cut slightly short due to a pit lane spin for Jimmie Johnson.

The seven-time NASCAR Cup Series champion looped the #48 Chip Ganassi Racing car at pit entry inside the final two minutes of the hour-long session.

While Johnson barely nicked his front wing on the wall on drivers’ left, the incident resulted in a Caution so that he could be wheeled out of the way by his crew, and Final Practice would not restart.

Rahal (Rahal Letterman Lanigan Racing) was therefore locked into first position, from Scott Dixon (Chip Ganassi Racing) and David Malukas (Dale Coyne Racing w/ HMD Motorsports), in what was an all-Honda top eight.

Will Power, who took a record-equalling 67th career pole position earlier in the day, ended up 17th in his Chevrolet-powered #12 Team Penske entry.

After the return of a special session designed to rubber in the top line, the same as that held at Texas, the full field was let loose for another 60 minutes of practice in the St Louis twilight.

Takuma Sato (DCR w/ Rick Ware Racing) was first to break 175mph when he set an early 175.710mph (282.778km/h), and that was the fastest lap until Alex Palou (Ganassi) clocked a 176.415mph (283.912km/h) lap in the 25th minute.

Romain Grosjean’s #28 Andretti Autosport Honda had an early sensor issue but he was firmly back on the pace when he raised the bar to 176.480mph (284.017km/h) at the half-hour mark.

Malukas took over top spot a few minutes later with a 176.724mph (284.410km/h) lap, but Grosjean was still second-quickest when he was heard reporting on his radio, “I don’t like the car at all.”

Dixon set a 177.459mph (285.593km/h) in the 43rd minute, before Rahal grabbed top spot with a 177.728mph (286.025kmh) with five minutes remaining.

That was the last change towards the top end of the timing screen, with Grosjean ending up fourth, from Palou, Marcus Ericsson (Ganassi), Sato, and Alexander Rossi (Andretti).

Josef Newgarden (Penske) was the only Chevrolet driver in the top 11, with Devlin DeFrancesco (Andretti) rounding out the top 10.

Scott McLaughlin (Penske) finished 16th on a 175.036mph (281.693km/h) and Power 17th on a 174.704mph (281.159km/h), while Christian Lundgaard (RLLR) wound up 20th after the lightest of touches with the wall exiting Turn 2.

Felix Rosenqvist, who had a minor crash in Qualifying, sat out the majority of the final practice session due to an unspecified technical problem in the #7 McLaren SP Chevrolet, which would be classified 24th in the 26-car field.

The next session is the race itself, on Sunday morning at 08:30 AEST.

Stan Sport’s live and ad-free coverage of that 260-lapper kicks off at 08:00 AEST.

Results: Practice 2