Colton Herta has become the youngest ever IndyCar pole-sitter while Will Power will start third in the 10th race of the season, at Road America.
Scott Dixon, however, failed to turn a lap in the second phase of qualifying after a mechanical issue beset his #9 Chip Ganassi Honda at the end of his first hit-out.
Herta clocked a 1:42.9920s in the #88 Harding Steinbrenner Racing Honda which put him 0.1773s clear of Alexander Rossi (#27 Andretti Autosport Honda).
Power (#12 Chevrolet) will be joined on the second row of the grid by Team Penske team-mate and series leader, Josef Newgarden (#2 Chevrolet).
Row 3 is an all-Rahal Letterman Lanigan affair with Graham Rahal (#15 Honda) edging Takuma Sato (#30 Honda) in the Fast Six.
While Dixon took 12th somewhat by default, team-mate Felix Rosenqvist (#10 Honda) went out at the first time of asking and will start 18th.
Ryan Hunter-Reay (#28 Andretti Autosport Honda) and Simon Pagenaud (#22 Team Penske Chevrolet) are only slightly better off with each putting in untidy laps on their way to 15th and 16th respectively.
The 55-lap race gets underway tomorrow at 0245 AEST.
Starting grid: Road America
|1||88||Colton Herta (R)||D/H/F||1:42.9920||Fast Six|
|2||27||Alexander Rossi||D/H/F||1:43.1693||Fast Six|
|3||12||Will Power||D/C/F||1:43.3749||Fast Six|
|4||2||Josef Newgarden||D/C/F||1:43.6036||Fast Six|
|5||15||Graham Rahal||D/H/F||1:43.8076||Fast Six|
|6||30||Takuma Sato||D/H/F||1:43.8790||Fast Six|
|7||18||Sebastien Bourdais||D/H/F||1:43.2989||Top 12|
|8||21||Spencer Pigot||D/C/F||1:43.3083||Top 12|
|9||5||James Hinchcliffe||D/H/F||1:43.3814||Top 12|
|10||98||Marco Andretti||D/H/F||1:43.3945||Top 12|
|11||20||Ed Jones||D/C/F||1:43.5162||Top 12|
|12||9||Scott Dixon||D/H/F||No Time||Top 12|
|13||31||Patricio O’Ward (R)||D/C/F||1:43.6061||Group 1|
|14||26||Zach Veach||D/H/F||1:43.4488||Group 2|
|15||28||Ryan Hunter-Reay||D/H/F||1:43.6980||Group 1|
|16||22||Simon Pagenaud||D/C/F||1:43.4764||Group 2|
|17||7||Marcus Ericsson (R)||D/H/F||1:43.8913||Group 1|
|18||10||Felix Rosenqvist (R)||D/H/F||1:43.5038||Group 2|
|19||60||Jack Harvey||D/H/F||1:44.6179||Group 1|
|20||4||Matheus Leist||D/C/F||1:43.8570||Group 2|
|21||19||Santino Ferrucci (R)||D/H/F||1:49.3060||Group 1|
|22||59||Max Chilton||D/C/F||1:43.8745||Group 2|
|23||14||Tony Kanaan||D/C/F||1:44.4183||Group 2|
(C)hassis: D=Dallara | (E)ngine: C=Chevy, H=Honda | (T)yre: F=Firestone