MONTREAL — American Venus Williams advanced to the second round of the Rogers Cup with a 7-5, 6-1 victory over Caroline Dolehide on Monday, before heavy rain delayed play on and off for three hours and was eventually suspended.

It looked like an upset was in the cards in the early going of the all-American matchup between Williams and Dolehide.

The 19-year-old Dolehide (No. 124), jumped to a 3-1 lead in the first set after breaking Williams' serve.

Dolehide, one of just two teenagers in the main draw, used her heavy service game and aggressive play to challenge Williams on every point. She finished the match with three aces. Williams had none.

But the 38-year-old veteran broke Dolehide back to take a 4-3 lead, and she did it again in the deciding game of the first set.

Dolehide, one of 12 qualifiers in the main draw, just couldn't maintain the same pace in the second set, as Williams only lost 11 points on her way to victory.

"It's never easy to play somebody you haven't played before, and she definitely has a lot of talent," said Williams. "She took advantage of it and I'm sure it's just a matter of time before she's able to play even better than today."

The seven-time Grand Slam champion will now face Sorana Cristea (No. 54) or Monica Niculescu (No. 69) in the second round.

Rainfall moved into the Montreal area just before 7:00 p.m. ET, interrupting two matches, including one in the first set between Russia's Maria Sharapova and Bulgaria's Sesil Karatantcheva.

With Sharapova leading 4-1 after 24 minutes of play, the match was delayed due to heavy rain and lightning.

Both players returned to the court three times to resume the match over the course of the three-hour delay, only for the rain to keep returning, forcing them back off the court.

Play was finally suspended at 10:30 p.m. ET. The match will resume Tuesday.

The encounter between Montreal's Francoise Abanda and Kirsten Flipkens of Belgium, which was supposed to begin after Sharapova's match, was also postponed to Tuesday.

In doubles action, Eugenie Bouchard and partner Sloane Stephens upset the fifth-seeded duo of Gabriela Dabrowski and Yifan Xu 6-4, 4-6, 1-0 (6).

"The reason I played doubles was to get more games under my belt," said Bouchard. "It's better than just a normal practice. I really worked on my service game, my volleys, my return. It can help with my singles game.

"Every victory can give you confidence."

Bouchard of nearby Westmount, Que., has only played in six doubles matches this season, including three with the American Stephens.

"We started playing doubles together in Washington last year," said Bouchard of her partnership with Stephens. "We have a lot of fun on the court. We laugh a lot. We're trying our best, obviously, but we're also really relaxed. It's good for both of our games."

In other singles play, 29-year-old Julia Goerges of Germany avoided an early loss with a 3-6, 7-6 (3), 6-4 win over Timea Babos of Hungary.

It took the 10th-ranked Goerges nearly two-and-a-half hours to complete the three-set comeback against the unseeded 25-year-old.

Goerges had 17 aces and five double faults to Babos' eight and one, respectively.

Goerges will face qualifier Lucie Safarova of the Czech Republic in the second round.

Also, Karolina Pliskova of the Czech Republic defeated Katerina Siniakova 6-4, 6-4 while Anett Kontaveit of Estonia defeated Ekaterina Makarova of Russia 4-6, 6-3, 6-1.