Li Na's impressive run at the Australian Open ended in the semifinal stage on Thursday when the Chinese 16th seed lost to defending champion Serena Williams in a tight, two-set thriller.

Li, who had knocked out three seeded players in previous rounds, including seven-time grand slam winner Venus Williams, cause much trouble for the world number one before going down 6-7 (4), 6-7 (1).

Serena advances to her fifth Australian Open final and will play either comeback queen Justine Henin of Belgium or Zheng Jie, another Chinese player.

It is the first time that two Chinese players have advanced to the last four at a grand slam tournament.