MELBOURNE: Defending champion Novak Djokovic crushed David Ferrer to reach the Australian Open final Thursday as Victoria Azarenka ignited a timeout row in setting up a women's title match with China's Li Na.

Djokovic, the world number one, floored Ferrer 6-2, 6-2, 6-1 in an embarrassingly one-sided contest which he rated as one of the best performances of his career.

“I just played incredible,” said the 25-year-old Serb, who will play either Roger Federer or Andy Murray in Sunday's final.

“I don't expect always to play this well but I was free in my mind tonight and I hope I can continue like this into the final.”

He added: “Today was my best performance, it came at the right moment and I hope I can play the same on Sunday.”

Djokovic was taken to five sets by a gritty Stanislas Wawrinka in the fourth round and he went four with Tomas Berdych in the quarter-finals, and the tireless Ferrer was expected to pose another test in the semi-final.

But the ultra-fit Serb played almost flawless tennis, hitting 30 winners with just 16 unforced errors, and will be the strong favourite to complete the first Australian Open title hat-trick since the 1960s.

“I played incredible tennis and I felt very comfortable and very confident from the start,” Djokovic said.

“I wanted to be aggressive on the court but this is definitely one of the best performances I've ever had in my career.”

The victory brought attention back to on-court action after Azarenka, last year's women's champion, found herself at the centre of a storm over a poorly-timed medical break in her semi-final with American teenager Sloane Stephens.

The increasingly flummoxed world number one had just lost five match points when she called for the trainer and went off the court for 10 minutes, with Stephens, 19, sitting in her courtside chair waiting to serve to stay in the match.

When Azarenka returned she broke Stephens to win 6-1, 6-4, and said she had avoided the “choke of the year” and felt “overwhelmed” before her break, suggesting she had needed to gather her thoughts rather than treat an injury.

After condemnation flooded in on TV and social media, Azarenka insisted her rib and knee problems were genuine and she apologised for the timing. But the incident raises questions about possible manipulation of timeouts.

“It was a necessary thing for me to do. I just regret that I didn't take it earlier, that it got to the point that it was pretty much impossible for me to breathe and to play,” Azarenka said.

Earlier Li, Asia's first Grand Slam singles champion, came out firing and halted Maria Sharapova's storming run with a blaze of aggression which stunned the four-time major champion 6-2, 6-2.

The Chinese world number six, who reaches her second Melbourne final, now has a chance to add to her historic 2011 French Open crown, which brought tennis to public attention in her home country.

“After playing for 20 years, this is the first time in my life,” she said, when asked if she had played a perfect match.

“At the beginning of the match I was nervous. I was happy I was back in the semis again, but for some reason I really wanted to win this match.

“I don't know what happened today. I just came to the court, feeling like, 'OK, just do it'. Yeah.”

Sharapova had lost only nine games in her march to the semi-finals, a tournament record, but Li was always going to provide a far sterner test despite trailing 4-8 in their head-to-head encounters.

And the Russian started disastrously with consecutive double faults as she was broken in the opening game, with Li's ball-striking putting her on the back foot from the outset.

In sweltering heat, Li's serving was steady, and her groundstrokes were probing as she closed out the opening set in 48 minutes, and maintained focus in the second as hard-hitting Sharapova ran out of ideas.

“I think she played a really great match. She was certainly much more aggressive than I was, dictating the play,” Sharapova said.

“I was always on the defence. When I had my opportunities and break points in games that went to deuce, I don't think any of them really went my way today.”