Toronto, Canada – By Ian Ransom
Against hard-hitting Li, however, the bravado disappeared all too quickly when challenged in the first set, and remained absent when the Chinese offered a number of opportunities to level in the second.
"I had my chances especially in the first set leading. I had my chance (to go to) 5-2 and didn't take it," a gloomy Wozniacki, who advanced to the fourth round without conceding a set, told reporters.
"I tried to hang in there but it just didn't go my way today."
The loss was her second in two weeks to the dangerous Li, who has proved her giant-killing credentials with wins over three top-10 players last year.
"Against her you need to just play on your highest level the whole match through and keep concentrated and keep a lot of balls in play," Wozniacki said.
The Dane played in some discomfort and had her leg strapped by a trainer while trailing 3-1 in the second, but said it "didn't affect the score at the end."
Having enjoyed the packed crowds of a grand slam center court far quicker than most players her age, Wozniacki now faces a lonelier, more introspective spell on the practice court.
"I need to go back and work and go back stronger," she said.
(Editing by Patrick Johnston)