Scott McLaughlin topped a heavily disrupted Practice session at Barber Motorsports Park ahead of Colton Herta and the reigning champion Will Power.
Scott Dixon set the fourth quickest time for Chip Ganassi as Marcus Ericsson rounded out the top five.
At the green light Kyle Kirkwood and a flurry of other cars joined the circuit at Barber to begin the 1 hour 15 minute Practice session.
After a brief lull in the session, Agustin Canapino set the first representative time of the session with a 1:12.8307 for Juncos Hollinger Racing on the Firestone Primary tyre.
The Argentinian bested his effort and drove to a 1:09.1456 with just over an hour to go, Canapino sat atop the timesheets ahead of his fellow rookies Sting Ray Robb and Benjamin Pederson.
Robb set the quickest time with an hour to go driving to a 1:07.9557 as all four rookies took advantage of their extra set of Primary tyres.
Former Formula 1 driver Romain Grosjean soon took the track for Andretti Autosport and went into second place as Danish driver Christian Lundgaard led the field.
Helio Castroneves got his Meyer Shank Racing car stuck in the gravel at Turn 9 and caused the red flags to be brought out, disrupting the session.
The Brazilian was able to continue after having his engine restarted by the AMR Safety Team in Alabama.
The session resumed after a short delay with 43 minutes to go, a multitude of cars joined the circuit to make up for lost time.
2021 IndyCar champion Alex Palou bested Lundgaard’s effort to top the timesheets for Chip Ganassi setting a 1:07.3779 as his team mate Ericsson slotted into third place.
Grosjean caused the second red flag of the session stopping out on the circuit as his Honda engine expired with 35 minutes to go.
The session resumed for the second time with 28 minutes to go as New Zealander McLaughlin soon improved to third place for Team Penske setting a 1:07.4239.
Palou improved his time atop the standings setting s 1:07.2709 as the times continued to tumble.
David Malukas set the first time of the session on the softer Alternate tyres with a 1:07.4101 as the six-time champion Scott Dixon jumped to the top of the timesheets.
Arrow McLaren SP’s Pato O’Ward made an error at Turn 14 but got away with it and managed to continue with 15 minutes remaining.
Frenchman Simon Pagenaud bested Dixon’s effort driving to a 1:07.1071 for Meyer Shank Racing as the track gathered more rubber.
Team Penske’s Power soon clattered the wall at Turn 3 causing the third red flag of the session as the the sole Practice session of the weekend became ever more disrupted.
Practice got underway again with 7 minutes to go. Lundgaard went quickest in spite of the fact his Rahal Letterman Lanigan car looked a handful.
Ericsson lapped quicker than the young Dane with a couple of minutes to go as the drivers set lap times on the red side walled Alternate tyres.
In the closing stages, McLaughlin jumped to the top of the timesheets with a 1:06.6610 with Herta just behind him for Andretti. Power improved to third place as the chequered flag fell in a mixed session for the Australian.
