Li Na of China is the first player to advance to the women's semi-finals at the Australian Tennis Open.
The ninth-seed overcame a shaky start to power her way through to the last four in Melbourne for the second year in a row, beating the German 30th seed Andrea Petkovic 6-2 6-4.
China's first top-10 player, was broken in the first game of each set but then attacked Petkovic's serve furiously to close out the match in 80 minutes at Rod Laver Arena.
Petkovic appeared nervous on her grand slam quarter-final debut and sprayed two forehands to concede the first set.
Li will play the top seed Caroline Wozniacki or Francesca Schiavone for a place in the final.
Last year she lost to Serena Williams in the semis.