Alex Palou set the pace in the first Practice of the GMR Grand Prix at Indianapolis for Chip Ganassi Racing.
Callum Ilott impressively finished in second just 0.0038 behind Palou in the first session.
Will Power set the third quickest time with the top three drivers separated by less than a tenth.
Christian Lundgaard a 1:10.8853 early on and eventually finished in P14 on his third visit to the Indy Road Course.
Dixon went quickest with 1:10.8632 going marginally faster than Lundgaard in the opening stages of the session.
Arrow McLaren SP driver Felix Rosenqvist soon went to the top of the times in first Practice as the track became more grippy throughout the session.
The Arrow McLaren SP team is hosting a third car for the GMR Grand Prix and Indy 500 with two-time Indy 500 winner Juan Pablo Montoya.
The Colombian settled in well on his return to IndyCar and set a 1:12.0074. He ended the session in P25 ahead of Dalton Kellett and Tatiana Calderon.
Will Power was the first Team Penske driver to top the times with a 1:10.6697, the first man to break the 1:10.7 barrier.
Halfway through the session Pato O’Ward, who won last time out at Barber, sat in P9 just three tenths behind Power who held the quickest time.
Romain Grosjean improved to P6 for Andretti Autosport at the circuit he claimed his first IndyCar podium in 2021.
Rookie driver Ilott impressively went to the top of the standings for Juncos Hollinger Racing with a 1:10.4593.
O’Ward ran wide at Turn 1 at went off the track with just a few minutes to go as he sat in eighth place.
Helio Castroneves caused a very late red flag with just two minutes to go at Indianapolis in the 06 car.
The session restarted with 1:38 left on the clock which saw a flurry of drivers go out on the track
2015 Indy 500 winner Alexander Rossi ended the season in P14 just ahead of Josef Newgarden.
Jimmie Johnson set the most laps of the session with 20 laps in the number 48 Chip Ganassi Racing car.
Palou went quickest right at the end going fractionally quicker than Ilott with a 1:10.4555.
Colton Herta had a quiet first Practice and eventually ended up in P10 for Andretti Autosport but did go quicker than both his teammates Grosjean and Rossi.