MELBOURNE, Australia - Showing the kind of fight only a World No.1 would have, Caroline Wozniacki fended off an inspired late surge from former No.1 Jelena Jankovic on Sunday night to reach the quarterfinals, 60 75.

Wozniacki, who is entering into her 67th career week as the No.1 player in the world, was a wall in the opening set, staying even with Jankovic in winners (seven each) but drawing three times as many errors (Wozniacki had six while Jankovic had 18). That pattern continued into the second set as Wozniacki would find herself on the verge of a blowout, a 60 41 lead on the scoreboard.

That is, of course, until a certain Serbian star broke the pattern.

"She started to play very well," Wozniacki said. "She had nothing to lose."

With some more down-the-lines and closing the net, the No.13-seeded Jankovic started to really take it to Wozniacki. She won four of the next five games - including saving a match point at 5-4 - to bring the set to 5-all, seemingly on the verge of a comeback. But as quickly as it turned, it turned again.

"When it was 5-4, 40-30, I was thinking, 'Okay, I need to get this point and I need to close it out.' It was like déjà vu from last year," Wozniacki said of the match point, where she hit a forehand into the net. "When it got to 5-all I said, 'Okay, doesn't matter. We're even here. Just keep going and fighting.

"In the second set she was starting to take her chances. She came to the net, played some great volleys, played some lines. I just kept focusing on the next point and not thinking about the score. I was really pleased to close it out."

Jankovic's analysis of the match was similar. "I saw the statistics after the match. I had 50 unforced errors and she had like 15. That's a huge difference. Here and there, in the first set too, I was up 40-15 in a lot of games, but I was erratic at times. I couldn't play consistently and keep it under control.

"Against a player like that who doesn't really give you anything, the best defensive player out there, I tried my best, but it just didn't happen."

The other night match saw Roger Federer beat young Australian Bernard Tomic, who is also doubling up as Jankovic's mixed doubles partner. She was asked about that. "It's going to be fun. Like a little consolation for us."

Awaiting Wozniacki in the quarterfinals is No.11 seed and defending champion Kim Clijsters, who pulled off a 46 76(6) 64 win over No.5 seed Li Na earlier in the day, coming back from quadruple match point down in the tie-break.

"I just need to play my game and play the same way as I did today. If I do, Kim really needs to play well to beat me," Wozniacki said. "It's important to think about myself and I believe I'm a great player. So if I lose to someone who just played better than me that day, I'll just take my hat off and say, 'Well done.'

"Kim is a great player. She has won a lot. She's done a lot throughout her career. I know it's her last Australian Open, so I'm sure she'll give everything. Today she had a really tough match against Li Na, and I thought she was out, but she showed her fighter heart and showed she can come back from any score. It's going to be a tough one. I'm really looking forward to it."

Clijsters has beaten Wozniacki in both of their previous meetings.