Andretti Autosport's Alexander Rossi claimed pole position for the first race of IndyCar's double-header around the streets of Belle Isle in Detroit.
An acrobatic lap from Rossi in the faster Group 2 session netted the American his sixth career pole, as he beat Scott Dixon by two-tenths of the session.
Team Penske's Josef Newgarden was quickest in Group 1 and will line-up from the outside of the front row.
Concerns over the durability of Firestone's alternate tyres kept drivers on primaries for the majority of the 12-minute Group 1 session, with Will Power (Team Penske) provisionally fastest.
But Chip Ganassi Racing's Felix Rosenqvist was the first car to nail a time on the alternates and went 0.45sec faster than Power's benchmark time.
Power then blew his first attempt on the reds by skating down the Turn 7 escape road, and then got a bad exit off the penultimate turn on his second flyer, improving only marginally on his primary-tyred run.
That allowed team-mate Newgarden to top Group 1 with a 1:14.8272s, ahead of Rosenqvist, and the Andretti pairing of Ryan Hunter-Reay and Zach Veach.
Schmidt Peterson Motorsport's James Hinchcliffe also jumped Power, consigning the Penske driver to the sixth row of the grid once the groups were combined.
The evolution of the track meant Dixon got within a tenth of Newgarden's benchmark early on, and his first lap on reds ensured Group 2 would be guaranteed pole.
But Dixon was thwarted by Rossi's stunning time of 1:14.1989s and Dixon, after a cool-down lap, tried to respond, but wound up two-tenths short, sealing third for the start.
Colton Herta will start fifth for Harding Steinbrenner Racing after turning the third-fastest time in Group 2, despite being called back to pits for a pitlane speed violation.
His former Indy Lights rival Patricio O'Ward was fourth-quickest in group, netting seventh on the grid for Carlin.
Indy 500 winner Simon Pagenaud had a disappointing session, 1.2568s off Rossi's top time, and will start on the row behind team-mate Power.
As the leaders of each group receive a point, as opposed to only the pole winner, Newgarden has drawn level with Pagenaud atop the standings.
|1||Alexander Rossi||Andretti Autosport||Dallara/Honda||1m14.1989s|
|2||Josef Newgarden||Team Penske||Dallara/Chevrolet||1m14.8272s|
|3||Scott Dixon||Chip Ganassi Racing||Dallara/Honda||1m14.3995s|
|4||Felix Rosenqvist||Chip Ganassi Racing||Dallara/Honda||1m14.9984s|
|5||Colton Herta||Harding Racing||Dallara/Honda||1m14.8811s|
|6||Ryan Hunter-Reay||Andretti Autosport||Dallara/Honda||1m15.1423s|
|8||Zach Veach||Andretti Autosport||Dallara/Honda||1m15.1487s|
|9||Takuma Sato||Rahal Letterman Lanigan||Dallara/Honda||1m15.3134s|
|10||James Hinchcliffe||Schmidt Peterson Motorsports||Dallara/Honda||1m15.1750s|
|11||Graham Rahal||Rahal Letterman Lanigan||Dallara/Honda||1m15.3945s|
|12||Will Power||Team Penske||Dallara/Chevrolet||1m15.2111s|
|13||Simon Pagenaud||Team Penske||Dallara/Chevrolet||1m15.4557s|
|14||Ed Jones||Ed Carpenter Racing||Dallara/Chevrolet||1m15.6341s|
|15||Marcus Ericsson||Schmidt Peterson Motorsports||Dallara/Honda||1m15.4811s|
|16||Sebastien Bourdais||Dale Coyne Racing||Dallara/Honda||1m15.6691s|
|17||Spencer Pigot||Ed Carpenter Racing||Dallara/Chevrolet||1m15.5621s|
|18||Marco Andretti||Andretti Herta||Dallara/Honda||1m15.8871s|
|20||Matheus Leist||AJ Foyt Enterprises||Dallara/Chevrolet||1m15.9628s|
|21||Tony Kanaan||AJ Foyt Enterprises||Dallara/Chevrolet||1m16.6842s|
|22||Santino Ferrucci||Dale Coyne Racing||Dallara/Honda||1m16.3830s|