Olympic champion Dementieva overwhelms Li

By Larry Fine

NEW YORK (Reuters) - Olympic champion Elena Dementieva, showing off her improved serve, breezed into the quarter-finals of the U.S. Open Sunday with a 6-4 6-1 victory over mistake-prone Li Na of China.

The fifth-seeded Russian, handicapped in the past by a weak and unreliable serve, dropped serve only once against the 36th-ranked Li and lost just 13 points in all from the service line.

Li attacked boldly but was missing badly, registering 28 unforced errors against just three winners in a disappointing follow-up to the Olympics where she reached the semi-finals with wins against Svetlana Kuznetsova and Venus Williams.

"I tried everything on court but it didn't work," Li told reporters after the one-hour match between the 26-year-olds.

"She hit the ball so deep. I didn't have a chance to play my game. She controlled every point of the match."

Dementieva, who at the beginning of the Open said her heart was still in Beijing after her greatest triumph, believed she was back on track at the slam where she has had her best results.

"It took me a week before I started to feel the ball and play a little better than in the beginning of the tournament," she said. "After playing four matches here, I feel pretty focused on this event."

Dementieva broke Li in her first two service games to charge to a 4-0 lead before the Chinese player rallied back, scoring a service break in the sixth game and holding break point that would have leveled the set in the 10th game.

But Dementieva averted the danger and prevailed on her second set point before crushing Li in the second set.

"Maybe because she won her last tournament, she's confident and thinks she can do everything," Li said. "She didn't miss a the ball."

Dementieva, the Open runner-up in 2004 and two other times a semi-finalist at Flushing Meadows, will meet 15th seed Patty Schnyder of Switzerland in the quarters.

(Reporting by Larry Fine; editing by Pritha Sarkar)