David Brabham fended off Simon Pagenaud to put Highcroft Acura on pole for the Mosport Park round of the American Le Mans Series.
Buoyed by having ended the De Ferran team's winning streak at Elkhart Lake two weeks ago, Brabham was dominant for much of prototype qualifying, leading the way by a second after his initial run and remaining on top thereafter.
Pagenaud gradually gained ground, and might have snatched pole away but for a violent ride over a kerb near the end of qualifying. The Frenchman had closed to within 0.074 seconds of Brabham, but had to settle for second.
"I don't think we ever showed what we could really do in practice, so we weren't too worried about that, but we knew it would be close in qualifying," said Brabham. "We were so, so close, and it just shows what a great race we're going to have."
The Dyson Lola-Mazdas took a commanding one-two in LMP2, although they will be split by the LMP1 Intersport Lola on the grid. Marino Franchitti claimed a second straight class pole in third overall, while the championship leading Fernandez Acura only managed third in class and sixth in the outright list.
Rahal Letterman BMW repeated the dominant GT2 form it had shown at Elkhart Lake, with Dirk Muller beating team-mate Joey Hand to class pole by 0.129sec.
"It's a perfect result for BMW again," said Muller. "It didn't look so good yesterday [in practice] but we really went deep into the car, worked hard and it gave us a really good car. It's been perfect."
The two works Corvettes will line up behind the BMWs, as the usual Porsche and Ferrari front-runners all ran into problems. Wolf Henzler was third in qualifying for Farnbacher Loles Porsche, but will have to start at the back under series rules as his teammate Dirk Werner missed today's sessions to race in the Montreal Grand-Am event.
Although the championship-leading Flying Lizard Porsche of Patrick Long and Jorg Bergmeister only managed fifth on the class grid, it is in far better shape than its title rival Risi Ferrari, which sat out the session after a heavy practice crash for Jaime Melo. The car's participation in the race remains in doubt while the team investigates whether chassis damage was sustained when the Brazilian went off at the first corner.