Dixon topped the 30-minute session around the 11-turn, 1.786-mile Exhibition Place street course with a best lap of 1m01.3208s.
The session started in damp conditions after a rainy and foggy start to the day, but the track quickly dried out with all cars on slick tyres. After a dry-wet-dry qualifying, many drivers had an abundance of tyres to use to get a final read on degradation over a stint.
Dixon set the early pace with 1m02.7294s after 10 minutes, with polesitter Christian Lundgaard (Rahal Letterman Lanigan Racing) getting within a tenth. Team Penske’s Scott McLaughlin and Felix Rosenqvist (Arrow McLaren) then got into an entertaining spat where they ran side-by-side, corner after corner.
Colton Herta, who will start 14th for Andretti Autosport, produced two laps in the 1m02.7s in succession, just 0.032s off Dixon for P2 at the halfway point, with the majority of times set on the primary tyres.
Lundgaard switched to the softer alternate rubber and took P1 with 1m02.7137s, shortly before David Malukas topped that with 1m02.7002s on the green-sidewalled Firestones.
Source: Autosport