China's Yan Zi upset Ana Ivanovic 6-3, 6-1 on Wednesday and eliminated the defending champion in the second round of the Rogers Cup.
Ivanovic the No. 4 seed was stunned by the 169th-ranked player in the world, capping a day of upsets that also claimed fifth-seeded Anna Chakvetadze and No. 8 Elena Dementieva.
"She's my favorite player," the 22-year-old Yan said. "I think today I'm really lucky."
She jumped on a lethargic Ivanovic, who won last week's East West Bank Classic in Los Angeles. Yan kept Ivanovic running with powerful two-handed strokes, never giving the 19-year-old Serb time to get comfortable.
"She played extremely well today," said Ivanovic, who won the tournament last year in Montreal. "I expected a tough match, but from the first point on she played very aggressively and she was dominating."
Yan came into the match relaxed, figuring she didn't have much to lose against a heavy favorite.
"Because she's the top player, I [didn't] think I could win," Yan said. "So [I] just went on the court and enjoyed the match."
Chakvetadze trailed 6-7 (5), 0-2 in her second-round match when she was forced to retire due to flu-like symptoms.
At least the top seed advanced. No. 1-ranked Justine Henin had an easy 6-3, 6-1 victory over Andreja Klepac of Slovenia and will next face China's Shuai Peng.
Sixth-seeded Nadia Petrova eliminated Canada's Stephanie Dubois with a three-set victory on a sunny, windy afternoon at the Rexall Center. Sybille Bammer knocked off another Canadian Aleksandra Wozniak, 6-4, 6-2.
Petrova started slowly but rebounded for a 6-7 (4), 6-2, 6-1 win.