Jankovic battles through knee injury to put down great Dane

Jelena Jankovic, you may or may not be surprised to learn, is ranked No 2 in the world and on the face of it that doesn't say a great deal about the world. Still, the 23-year-old from Belgrade overcame two handicaps yesterday, a suspect left knee and an admirable adversary.

Caroline Wozniacki, experiencing the rarefied heights of the third round at Wimbledon for the first time in her young career, did herself, her country, Denmark, and the women's game proud with a performance that, at times, lit up the Centre Court.

Wozniacki, at just 17, is a star in the making. Playing with a maturity and confidence beyond her years, she took the first set 6-2 and another major upset was on the cards until the Serb's weight of shot gradually began to wear her opponent down.

Jankovic, who won the mixed doubles here with Jamie Murray last year, prevailed 2-6 6-4 6-2 in a contest that lasted two hours and five minutes. At least that's what the Rolex said, although the actual playing time was a bit shorter. After levelling the match at a set apiece, Jankovic called for the assistance of the trainer, who trooped on, rucksack on back, looking as if she'd yomped from Land's End.

There has been an inordinate number of withdrawals from these championships and for a while it looked as if Jankovic, who has never been beyond the fourth round, would join them. Before the start of the final set she had her left knee examined and then the joint was strapped up with enough tape to shroud a mummy.

"I slid in the first set and my leg went straight and then bent so quickly," Jankovic said. "There was a sharp pain but I continued to play and it was getting worse and worse. On grass you have to stay low and bend a lot. I was struggling a bit but somehow came through. It's very sore now. I'll have a scan. I don't think it's that bad."

As in the second set, Wozniacki lost her serve in the opening game, surprised perhaps by her opponent's mobility in spite of the tourniquet. Between points Jankovic staged a sort of go slow, grimacing behind the baseline and clutching the dodgy knee. However, during the rallies, of which there were plenty, she was running around like a spring, free-range, chicken.

With Jankovic leading 3-2, the trainer reappeared, this time to remove the yards of tape that had been so lovingly applied. "The physio wasn't happy about that but with the tape I felt like I couldn't move." It didn't stop her expressions of discomfort, nor in winning her next service game to love. Another break of serve enabled her to open up a 5-2 lead and the teenager from Copenhagen had reached the end of the road. At least in the singles. She barely had time to reflect on her defeat before regrouping for a doubles contest.

With the abrupt departures of Maria Sharapova and Ana Ivanovic, Jankovic is the highest seeded player left in the women's draw. Can she win, à la Tiger Woods, on one leg? She will struggle on two.

She was exposed by the potentially great Dane, a former Wimbledon junior champion, in the first set – how can the land of Legoland, bacon and beer produce a contender here while all the Brits had long gone home? – as Wozniacki, wearing ankle guards, produced serves approaching 110mph. In chasing down shots she was more of a terrier than a Dane and her impressive double-handed backhand was more often than not a winner. Another feature of the match was the number of challenges both players made and calls were often made by margins smaller than the width of a cigarette paper.

"My opponent didn't have anything to lose," Jankovic said. "Her body's quite strong and mature for her age. She's very young. I didn't know she was that young. Of course I'm more experienced and have played many more matches on Centre Court. I'm the No 2 seed, the No 2 in the world." It's still hard to believe.

Elsewhere, the Duracell lady, Ai Sugiyama of Japan, was defeated 6-4 6-4 by the Russian Alisa Kleybanova. Sugiyama was making her 16th consecutive visit to the championships, the most of any player in the ladies' singles, and was setting a record with an uninterrupted sequence of 57 Grand Slam appearances dating back to 1994.

Joining Kleybanova in the fourth round was her compatriot Elena Dementieva, who put out the Argentinian Gisela Dulko, also in straight sets, 7-6 7-5, despite losing the first four games. Dementieva will now meet Shahar Peer of Israel, who had a famous and hard-earned victory over the ninth-seeded Russian, Dinara Safina.

Dementieva, the fifth seed, had played Dulko on two previous occasions. "I'd never beaten her before so maybe in the beginning I felt a bit nervous," Dementieva said. "At love-four I just decided not to think about the score but to play every single point and focus on the game.

"Initially I was just standing there and waiting for mistakes that she didn't make. I'm going to have to work more to play better here."

It's that old work ethic again which somehow, in the home counties, seems to be conspicuous by its absence.