The Rogers Cup lost power both figuratively and literally on Tuesday with hometown favourite Eugenie Bouchard suffering a second round defeat to American qualifier Shelby Rogers.
The 20-year-old Bouchard, playing for the first time since losing in the Wimbledon final to Petra Kvitova last month, faltered badly in front of her native Montreal crowd.
Her 6-0 2-6 6-0 loss came after the event suffered a seven-hour power outage that shut down scoreboards and umpires' microphones.
Bouchard suffered her own issues out of the gate as she struggled with her serve and failed to claim a game in the opener.
She rebounded to dominate the second set but again showed rust in the decider, ending the anticipated quarter-final match between top-ranked Serena Williams and Bouchard.
Williams had the day off but her older sister Venus fought her way to a three-set victory against Anastasia Pavlyuchenkova 6-1 3-6 6-2 despite the electrical conditions.
"It was like going back to the southern California juniors," Venus told reporters of the power outages.
"But I tried to think of it as positive. It felt good to win the match and hopefully gain some momentum."
In other matches, Caroline Wozniacki made easy work of Daniel Hantuchova in a 6-1 6-1 triumph, while third-seed Agnieszka Radwanska defeated Barbora Zahlavova-Strycova 6-4 6-4 and ninth-seed Ana Ivanovic routed Timea Bacsinszky 6-1 6-2.
Spain's 14th seed Carla Suarez-Navarro and 16th-seed Elena Vesnina also advanced to the second round after respective victories over Bojana Jovanovski and Camila Giorgi.