Any match between Li Na and Caroline Wozniacki is going to reside on the Chinese woman’s racquet. Stat-wise, though, their quarterfinal on Wednesday night in Miami bordered on the ridiculous. Wozniacki’s total combined winners and errors for the match: 28. Li’s total: 80. Win or lose, Li was in the driver’s seat.

Li ended up driving away with a 7-5, 7-5 victory, and she won both sets in similar, customarily streaky fashion. She started well in each, endured a horrific middle stretch littered with unforced errors, and then righted herself just in time. And when Li went right this time, she really went right. The world No. 2 finished the first set by winning 12 of 14 points; she finished the second by winning 14 of 17. Li is always up and down, but credit her tonight for forgetting her mistakes in a hurry and, in the blink of any eye, replacing her worst tennis with her best exactly when she had to have it.

Wozniacki, despite another barrage of mid-match advice about her forehand from her father, struggled to make any inroads with that shot. She was two points from winning the first set at 5-4, yet she finished it with just a single winner. In this case, she may have felt that the best tactic was to wait for Li to make mistakes, and she was almost right. Li made enough of them to let Caro get to 5-4, 30-30 in the first, and 5-3 in the second. But when Li found her range again, Wozniacki had no answers.

At 2-1 in the second set, Wozniacki called the trainer for a back problem; she said she had trouble moving to her forehand side. But in the end it was, uncharacteristically, her patience and composure that failed her. At 4-5 in the second, she was on the wrong end of a bad overrule by the chair umpire; the point was replayed, Wozniacki lost it, and lost her cool in the process. Still agitated about the call a game later, she folded quickly at the end.

Li won’t be happy with an error count of 49, but she will be happy with the way she handled adversity. She may be even happier to see who her opponent is in the semifinals: Dominika Cibulkova, a woman she has beaten twice already this season, and all six times they’ve played.