World number two Li Na posted a 7-5, 7-5 victory over 11th seeded Caroline Wozniacki in the quarter-finals of the WTA and ATP Miami Masters tournament on Wednesday.
China's Li won 63% of her first serve points and 79 of 150 total points in the match which lasted just over two hours.
Li advances to the semi-finals where she will face Dominika Cibulkova of Slovakia who beat Agnieszka Radwanska in three sets earlier in the day.
Cibulkova is winless in six career meetings against Li, including a loss in the final of this year's Australian Open.
Thursday's other semi-final sees world number one Serena Williams against fourth-seeded Maria Sharapova.
The American defeated Sharapova in last year's final to capture a sixth Miami title, sending Sharapova to her fifth loss in five finals.