41 Errors Cost Li Na Match Against Clijsters

When it came to serves and the power of her strokes Li Na was easily a match for Kim Clijsters. What cost her the match and a spot in the U.S. Open Semis was 41 unforced errors to 25 for Clijsters. Li managed to tighten up her ground strokes but the differential was enough to cost her a 6-2, 6-4 defeat.

Li’s first serve percentage was higher than Clijster’s, at 80% vs 73%. The speed of Li’s serves, at a top speed of 106 mph, was identical to Clijster’s. Their average speeds, at 97 for first and 84 for 2nd, were nearly the same as Clijster’s 98 and 85. Yet Li seemed unable to sustain her focus long enough to string together games.

The mother of 18-month-old Jada, Clijsters was far more consistent with her groundstrokes, and she played nearly as well as she did before retiring two years ago.

At times, even a bit better.

The 26-year-old Belgian is back at the U.S. Open for the first time since 2005, when she won the tournament, and now has a winning streak of 12 matches at Flushing Meadows. Her next match will be against the winner between No. 2 Serena Williams and No. 10 Flavia Pennetta.

Clijsters has already beaten No. 3 Venus Williams and two other seeded players, and nothing seems like too big a stretch at this point.

“I’m glad I got through it again, stayed focused on my game,” Clijsters said. “I wanted to be aggressive and I think that’s what helped winning those important points today.”

The few important points there were in this one came midway through the second set, after Clijsters had lost a break to turn a 3-1 lead into a 4-4 tie. Li responded with four unforced errors to give away the ninth game and the match was over a few minutes later.

Clijsters became the first unseeded player to make the U.S. Open semifinals since Elena Dementieva in 2000. Clijsters was unranked because she hadn’t played enough tournaments in her comeback to get on the board, but she’ll be in the low-50s or better when the next rankings come out.

As efficient as she has been — moving better now than she did when she was constantly battling injuries toward the end of her last stint — her run through this tournament might also be seen as a statement about the state of women’s tennis.

Serena Williams is the only top-five seed left. Three of the players on the opposite side of the draw — the “Melanie Oudin side” — are ranked 50 or higher, joined by No. 9 Caroline Wozniacki. All are playing in their first major quarterfinals.

“I saw her when she came back in her first tournament,” Li said, referring to Clijsters. “I knew she was at a high level. She’s much stronger than other girls, so I knew, if she was going to come back, it must be a strong comeback.”

The men’s tournament, meanwhile, is going much more to form.

Roger Federer breezed through his fourth-round match Monday with a 7-5, 6-2, 6-2 victory over No. 14 Tommy Robredo for his 38th straight win at the U.S. Open. The world’s top player is going for his sixth straight title at Flushing Meadows.

Clijsters’ match was followed by one between No. 2 Andy Murray and No. 16 Marin Cilic.

Third-seeded Rafael Nadal, winning less impressively so far — possibly because of an abdominal injury that caused him to call for the trainer in his last match — had a match against No. 13 Gael Monfils later Tuesday.

9/8/2009 2:52 PM EDDIE PELLS, AP National Writer NEW YORK