Gustavo Yacaman and Olivier Pla won the United SportsCar Championship race at Mosport Park in a dominant lights-to-flag victory.
Poleman Yacaman in the OAK Racing Protoype sped off the line from the charging Spirit of Daytona Corvette of Michael Valiante on a drying track following morning rain showers.
The Colombian stayed in the car in the first round of stops, as did Valiante, but Valiante's change to Richard Westbrook after an hour and a half for the second pit stop was slow.
The #90 Spirit Corvette then ran with a gearbox problem which caused Westbrook to lose time during his stint - allowing Jordan Taylor to move up to second in his Wayne Taylor Racing machine.
Yacaman's change with team-mate Olivier Pla was much smoother, and they maintained their lead in an afternoon of flawless stops.
Taylor pitted 45 minutes from the end in the final fuel stop in an attempt to undercut the other Prototype teams, but another clean stop from OAK Racing kept it in the lead.
A strong stint from Westbrook towards the end allowed him to catch up onto the tail of Taylor, finally passing him for second with less than half an hour remaining, also cutting the gap to Pla from 30 seconds to seven.
Christian Fittipaldi showed strong pace in the Action Express Corvette from the start, but when championship leader Ricky Taylor attempted to barge his way through in the early moments Fittipaldi was shown the black and white flag and forced to pit.
He then suffered damage 25 minutes later when his left rear tyre delaminated after hitting a GT Daytona competitor, and a slow pit stop to replace the wheel did little to help his race, dropping him back to finish fourth overall with team-mate Joao Barbosa.
The Extreme Speed Motorsports team had a day to forget, with both of its entries having to retire.
CORVETTE AND VIPER SHARE GT HONOURS
In the GT Le Mans class Jan Magnussen and Antonio Garcia took their fourth successive win.
Magnussen was hounding leader Kuno Wittmer in the early laps, but the SRT Motorsports driver took an excursion onto the grass 55 minutes in and collected an advertising board and also spread turf across the track.
The contact handed Magnussen and Garcia the win, with the #93 and #91 SRT Vipers of Bomarito and Goosens rounding out the podium.
The GTD class was won by Jeroen Bleekemolen and Ben Keating in the #33 SRT Viper, overtaking the Kevin Estre/Patrick Lindsay driven Porsche 911 with less than a minute to go.
Dane Cameron and Markus Palttala's BMW Z4 finished third.
Leading results - 133 laps:
Pos Cl Drivers Team/Car Time/Gap
1. P Yacaman/Pla OAK Morgan-Nissan 2h45m32.479s
2. P Westbrook/Valiante Spirit Corvette DP +7.886s
3. P Taylor/Taylor Taylor Corvette DP +20.943s
4. P Fittipaldi/Barbosa Action Express Corvette DP +1m10.730s
5. P Negri Jr/Pew Michael Shank Riley-Ford -2 laps
6. GTLM Garcia/Magnussen Corvette -6 laps
7. GTLM Bomarito/Wittmer SRT Viper -6 laps
8. P Miller/Nunez SpeedSource Mazda -6 laps
9. GTLM Goosens/Farnbacher SRT Viper -6 laps
10. GTLM Edwards/Muller RLL BMW -7 laps