The 28-year-old Aussie threw the gauntlet with a flying lap of 1m13.672s on the 14-turn, 2.439-mile circuit to claim bragging rights at team owner Roger Penske’s track in the #7 Porsche 963.
It marks the second pole of the year for Campbell.
It became a front-row lockout for Porsche Penske Motorsports after Mathieu Jaminet came across the line 0.152s off his team-mate.
Jaminet was briefly bumped from second by Meyer Shank Racing’s Tom Blomqvist before returning the favor in the final minutes and knocking the #60 Acura ARX-06 to third.
Sebastien Bourdais came away fourth in Chip Ganassi Racing's #01 Cadillac V-Series.R, followed by points leader Ricky Taylor, who overcame an early Turn 2 spin to put the #10 Wayne Taylor Racing with Andretti Autosport entry fifth.
Source: Autosport