Canadian Eugenie Bouchard is out of the Rogers Cup in the first round for the second straight year.

Bouchard lost to Switzerland's Belinda Bencic 6-0, 5-7, 6-2 Tuesday night on centre court at Aviva Centre.

The 21-year-old from Westmount, Que., has now lost her first match in eight of her past 10 WTA tournaments. Bouchard has also dropped 13 of her past 15 matches overall.

Bencic, the 20th-ranked player in the world, moves on to face fourth-seeded Caroline Wozniacki in the second round.

"It was a big fight," Bencic said immediately after the match. "I think Genie played very good."

Bouchard's struggles began a year ago when the Rogers Cup was in Montreal and she lost to qualifier Shelby Rogers when ranked fifth. While that was a stunning defeat on the heels of her finals appearance at Wimbledon, this loss followed a year-long trend.

Amid her struggles, Bouchard has fired two coaches -- Nick Saviano in November and Sam Sumyk last week. Bouchard said she was working with Marko Dragic on a short-term basis for the Rogers Cup.

Bouchard's exit means there are no Canadians left in women's singles play.

Francoise Abanda of Montreal lost to 16th-seeded Andrea Petkovic of Germany 3-6, 6-4-6-2, and Carol Zhao of Richmond Hill, Ont., lost 6-1, 6-1 to American Madison Brengle.

Earlier Tuesday, world No. 1 Serena Williams survived an early scare to beat Italy's Flavia Pennetta 2-6, 6-3, 6-0. Williams was frustrated with how she was playing and then got too angry to focus.

"I said, 'Serena, you're going to have to be positive and be good to yourself out here,"' Williams said. "Once I started being more positive, I started actually playing better, too."

Williams is the only player back for this Rogers Cup who played in 2001, when she won the tournament for the first time. Asked how that made her feel, Williams said: "Like a nice vintage wine. A good vintage red wine, I'd say, getting better with age, I hope."

Even at 33, Williams is playing elite-level tennis and can complete the calendar-year Grand Slam by winning the U.S. Open next month. She's using this tournament to get used to playing on hard courts again.

It was a good opportunity for me because I haven't played a match on hard courts since April-ish, early, early April, after Miami," Williams said. "It was a long time ago. So I think it was really good for me to have that match play."