Helio Castroneves has pipped Will Power to pole position for the Road America IndyCar race as Team Penske locked out the first two rows of the starting grid.
Such was the Penske Chevrolets' dominance, they swept the top four in both Friday's Practice 2 and the day's earlier Practice 3 session, led on those occasions by Josef Newgarden and Simon Pagenaud respectively.
In the three-stage qualifying, Power and Newgarden went one-two in Round 1/Group 1, Pagenaud and Castroneves did the same in Round 1/Group 2, then Castroneves led a top four sweep of Round 2 of qualifying.
Castroneves' final lap of qualifying was enough to edge Power by just 0.06s, earning the Brazilian his 50th IndyCar pole.
Behind them, Newgarden and Pagenaud were each a few tenths further back, giving Penske its fourth one-two-three-four in qualifying in history.
All were comfortably clear of the other two men to make the Fast 6, with Scott Dixon more than 1.6s off pole and nearly 0.9s adrift of Pagenaud in the New Zealander's Chip Ganassi Honda.
Graham Rahal opted against using his red tyres in the Fast 6 and was never a factor in the final stage of qualifying in his Rahal Letterman Lanigan Honda.
Max Chilton (Chip Ganassi Honda) missed the Fast 6 by 0.06s and will start seventh, with the top 10 rounded out by Marco Andretti (Andretti Autosport Honda), James Hinchcliffe (Schmidt Peterson Honda), and Charlie Kimball (Chip Ganassi Honda).
Mikhail Aleshin (Schmidt Peterson Honda) overcame visa issues to arrive at Road America in time for Saturday practice before qualifying in 19th position, one ahead of Indianapolis 500 winner Takuma Sato (Andretti Autosport Honda).
Race start is Monday morning at 0315 AEST.
Qualifying: Road America Grand Prix
Pos | Driver | C/A/E/T | Time | Session |
1 | Helio Castroneves | D/C/C/F | 01:41.3007 | Fast Six |
2 | Will Power | D/C/C/F | 01:41.3611 | Fast Six |
3 | Josef Newgarden | D/C/C/F | 01:41.6608 | Fast Six |
4 | Simon Pagenaud | D/C/C/F | 01:42.0385 | Fast Six |
5 | Scott Dixon | D/H/H/F | 01:42.9308 | Fast Six |
6 | Graham Rahal | D/H/H/F | 01:45.0464 | Fast Six |
7 | Max Chilton | D/H/H/F | 01:42.7566 | Round 2 |
8 | Marco Andretti | D/H/H/F | 01:42.8614 | Round 2 |
9 | James Hinchcliffe | D/H/H/F | 01:43.2105 | Round 2 |
10 | Charlie Kimball | D/H/H/F | 01:43.3221 | Round 2 |
11 | Ed (R) Jones | D/H/H/F | 01:43.7959 | Round 2 |
12 | Ryan Hunter-Reay | D/H/H/F | 01:43.9786 | Round 2 |
13 | Carlos Munoz | D/C/C/F | 01:42.9039 | Round 1 / Group 1 |
14 | Spencer Pigot | D/C/C/F | 01:42.8875 | Round 1 / Group 2 |
15 | Alexander Rossi | D/H/H/F | 01:43.0171 | Round 1 / Group 1 |
16 | Tony Kanaan | D/H/H/F | 01:42.9077 | Round 1 / Group 2 |
17 | Esteban Gutierrez (R) | D/H/H/F | 01:43.1652 | Round 1 / Group 1 |
18 | JR Hildebrand | D/C/C/F | 01:42.9132 | Round 1 / Group 2 |
19 | Mikhail Aleshin | D/H/H/F | 01:43.8891 | Round 1 / Group 1 |
20 | Takuma Sato | D/H/H/F | 01:43.4111 | Round 1 / Group 2 |
21 | Conor Daly | D/C/C/F | 01:44.1579 | Round 1 / Group 2 |
(C)hassis: D=Dallara | (A)erokit: C=Chevy, H=Honda | (E)ngine: C=Chevy, H=Honda | (T)yre: F=Firestone