TORONTO - Belinda Bencic leaned against the back wall on the grandstand court at Aviva Centre on Thursday afternoon and tried to forget about her frustration from the previous two hours.

Needing to hold serve to force a tiebreaker and keep her strong run at the Rogers Cup alive, she held a steely gaze as Sabine Lisicki had her wrist taped on the other side of the net. Bencic had already knocked off Caroline Wozniacki and Canada's Eugenie Bouchard this week and wanted her German opponent to be next.

The medical timeout gave Bencic a chance to collect her thoughts. When play resumed, there was no stopping her.

She held serve at love — capping the game with an ace — before giving up just three points in the tiebreaker for a 6-1, 1-6, 7-6 (3) victory.

"In that moment actually I really tried to go for it," she said. "I served better and I'm happy that I could play my best in the important moments."

The two players were evenly matched and employed similar styles. Strong ground strokes often set up aggressive winner attempts but both players had their struggles with unforced errors.

Bencic was relentless in the opener before Lisicki returned the favour in the second set.

The rising Swiss star didn't hide her frustration when things didn't go her way. The fiery 20-year-old tossed her racket to the ground on several occasions and at one point, launched a spare ball way up in the air after her serve was broken.

However, Bencic managed to keep her emotions in check when it mattered. She'll next face either fifth-seeded Ana Ivanovic of Serbia or Slovenian qualifier Polona Hercog in the quarter-finals.

"I am like that — I get frustrated really fast, but I also calm down really fast," Bencic said.

At the same time, second-seeded Simona Halep survived a stiff test against Germany's Angelique Kerber. The Romanian advanced with a 6-3, 5-7, 6-4 victory.

Service breaks were the norm in the last set of the two-hour 23-minute match as both players had trouble generating power under the hot sun on Centre Court.

"I did well in the last game," Halep said. "I said that I have to win it because I cannot move anymore."

In other matches Thursday, Italy's Roberta Vinci advanced with a 6-4, 6-3 victory over Daria Gavrilova of Russia and Ukraine's Lesia Tsurenko topped Carina Witthoeft of Germany 6-3, 6-4 in a battle of qualifiers. Sixth-seeded Agnieszka Radwanska of Poland defeated Alize Cornet of France 6-2, 4-6, 6-4 and 15th-seeded Sara Errani of Italy beat Belarusian Victoria Azarenka 7-5, 6-3.

Top-seeded Serena Williams of the United States earned a straight-sets victory 6-3, 6-2 over 16th-seeded Andrea Petkovic of Germany, while fifth-seed Ana Ivanovic topped Polona Hercog of Slovakia 6-2, 6-3 in the evening draw.

"I think I served better," Williams said. "It was a big difference. I still think I have a tremendous amount of improvement to do off the ground and everywhere else."

In second-round doubles play, the Canadian duo of Sharon Fichman and Carol Zhao defeated second-seeded Ekaterina Makarova and Elena Vesnina. Fichman, from Toronto, and Zhao, from Richmond Hill, Ont., were ahead 5-2 when the Russian team retired.

Francoise Abanda of Montreal and Heidi El Tabakh of Toronto dropped a 6-3, 6-2 decision to fourth-seeded Caroline Garcia of France and Katarina Srebotnik of Slovenia.

Bencic, who won her first WTA Tour singles title earlier this year at Eastbourne, has also captured a pair of doubles titles in 2015. She was scheduled to team with Slovakia's Dominika Cibulkova on Thursday night against Errani and Italy's Flavia Pennetta.

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