NEW YORK, Sept 5 - (Reuters) - Venus Williams and Kim Clijsters passed their first real tests at the U.S. Open with flying colors on Sunday to safely book their places in the quarter-finals.
The pair could hardly have been more impressive as they swept past tricky fourth-round opponents to remain on course for a blockbuster semi-final showdown when the last the last grand slam of the season enters the second week.
Williams, the champion at Flushing Meadows in 2000 and 2001, defeated Israeli 16th seed Shahar Peer 7-6 6-3 and the American said the match was the perfect test for what was ahead of her.
"It's always good to have a tougher match, a kind of a match where you have to challenge yourself against your opponent and the conditions," Williams said.
"We always have had very competitive matches, so I know it's not going to be something I just walk through when I play against her.
"I have to stay focused and ready to take every point or else she will. It was a good challenge."
Clijsters, who won the title in 2005 and again last year, thrashed Serbia's former world number one Ana Ivanovic 6-2 6-1 in just under an hour. Like Williams, she is yet to drop a set in the championship.
"You always want to do well at tournaments where you've done well, and obviously, the U.S. Open is a special tournament for me," Clijsters said.
"Tennis wise, I feel that I've been improving every match. I want to try and keep it going."
Italy's Francesca Schiavone, brimming with confidence after winning her maiden grand slam title at this year's French Open, also cruised through in straight sets, beating Russia's Anastasia Pavlyuchenkova 6-3 6-0.
Schiavone will play Williams in Tuesday's quarter-finals while Clijsters will face the winner of Sunday's late match between Samantha Stosur and Elena Dementieva.
"I feel better than when I was in French Open, but just because I know how to do it and how to win a match like this," Schiavone said.
"So I'm very curious, I'm interested to see (if I can) write a new history."
Spain continued their assault on the men's draw with Fernando Verdasco, David Ferrer and Felciano Lopez all sealing their places in the fourth round.
They followed their countryman Albert Montanes, who made it through to the last 16 on Saturday, and could be joined by another two Spaniards with Rafa Nadal and Tommy Robredo yet to play their third-round matches.
"It's always nice to see all the Spanish winning and being in the last rounds," said Verdasco, who advanced with a four set win over Argentine David Nalbandian.
Editing by Steve Ginsburg