EDMONTON, Alberta -- As the City Centre Airport circuit dried from overnight rain, the times progressively dropped during the 45-minute qualifying session for the Firestone Indy Lights Edmonton 100.

So the final three minutes proved to be the most crucial for lap times on the 2.224-mile, 13-turn course in chasing the pole, especially the drivers' last lap. Carlos Munoz won that race, guiding the No. 26 Team Dialy-Ser car to a lap of 1 minute, 25.5115 seconds on his 23rd lap of the session.

It was the first pole for 20-year-old from Colombia, whose previous best start in his rookie Firestone Indy Lights season for Andretti Autosport was third at Barber and Indianapolis.

Click it: Edmonton 100 starting lineup

"It was a really difficult session. In the beginning it was really, really wet, but step by step I knew that the track would get dry and drivers in the beginning were not really pushing," said Munoz, who topped the time chart in practice a day earlier. "I learned in Toronto that I wanted to push a lot. So, in the end, it was my last lap, and I pushed like it was the last lap of my life."

The 40-lap race is scheduled to take the green flag at 5:30 p.m. (ET), with more rain forecast. Keep track of the action with the IMS Radio Network's broadcast and real-time Timing & Scoring on www.indycar.com.

Peter Dempsey, driving the No. 9 TrueFuel car for Belardi Auto Racing, was atop the time chart for much of the session, and kept lowering his lap times to stay ahead of the competition. His best lap (23 of 25) was 1:25.5504 -- 0.0389 of a second short of Munoz's time. It's Dempsey's third Firestone Indy Lights front-row start, and first of the season.

Esteban Guerrieri and Tristan Vautier, the top two in the championship standings, will share Row 2. Guerrieri, driving the No. 11 Pistas Argentinas/Sam Schmidt Motorsports with Curb Agajanian car, had a best lap of 1:25.7204. Vautier was a tenth of a second behind in the No. 77 Mazda Road to Indy/Sam Schmidt Motorsports with Curb Agajanian car.