Azarenka, the third seed from Belarus, will be playing in her first Grand Slam final. She will face either fourth-seeded Maria Sharapova, the 2008 Australian Open champion, or Wimbledon champion Petra Kvitova, who is seeded second.
After being routed in the second set, Azarenka took a 4-1 lead in the third. Clijsters cut the deficit to 4-3 but was broken to give Azarenka a 5-3 advantage.
Serving for the match, Azarenka took a 40-0 lead, but double-faulted on her first match point. On the second match point, Clijsters hit a backhand wide, ending it.
Djokovic in semis. With Novak Djokovic clutching his leg and struggling to breathe, it looked like the "Big 4" semifinal lineup might not come together. Then Djokovic's championship instincts kicked in.
The top-ranked Serb held off No. 5 David Ferrer in a second-set tiebreaker last night and then raced through the third set for a 6-4, 7-6 (4), 6-1 win, setting up a rematch of last year's final against fourth-ranked Andy Murray.
Order was restored.
For 10 days, nearly everyone at Melbourne Park has talked about the top four players and how they are on a higher level than the rest of men's tennis. But with the other three already in the semis, Djokovic looked to be in trouble in the second set.
"No, I don't have any physical issues," Djokovic said, playing down any health concerns. "I feel very fit and I feel mentally, as well, very fresh.
"It's just today I found it very difficult after a long time to breathe because I felt the whole day my nose was closed a little bit. I just wasn't able to get enough oxygen."
The win ensured that the top four men reached the semifinals for the third time in four Grand Slams. Murray beat Kei Nishikori, 6-3, 6-3, 6-1, earlier, while second-ranked Rafael Nadal and No. 3 Roger Federer already were preparing for their semifinal showdown, their 10th clash at a major.