New York ? Cutting short the chance to rest during a changeover, Jennifer Capriati hopped off her chair and headed to the baseline.

Enough waiting around already, Capriati was thinking, let’s get this over with.

In a rain-interrupted match that ended 61/2 hours after it began, No. 6-seeded Capriati reached the U.S. Open quarterfinals for the third straight year by topping No. 11 Elena Dementieva 6-2, 7-5 Monday.

“It was just getting pretty annoying. I was getting tired,” Capriati said. “It’s hard to play matches like that once you’re out there because your rhythm is off.”

Downpours washed out all men’s action, and Capriati’s was one of only two matches completed. French Open champion Justine Henin-Hardenne started her fourth-round match shortly before 10:30 p.m., and she was off the court quickly, beating Dinara Safina 6-0, 6-3 in 57 minutes to make the Open’s round of eight for the first time.

After Henin-Hardenne and Safina, the younger sister of 2000 Open champion Marat Safin, warmed up, tournament referee Brian Earley made them sit while he inspected the court. With the No. 2-seeded Henin-Hardenne urging him to let them play, Earley did.

“It’s been a long day,” Henin-Hardenne said. “Tomorrow I have a day to rest, so that’s going to be perfect.”

Fewer than 50 fans were on hand at the Grandstand Court when No. 7 Anstasia Myskina and two-time Grand Slam title winner Mary Pierce began their encounter a little after 11 p.m. When play was stopped for the day at 11:41 p.m., Myskina led 4-2 in the first set, while No. 15 Ai Sugiyama and No. 29 Francesca Schiavone were tied 6-6.

A total of 69 matches — including ones in the doubles, junior and senior tournaments — were postponed without a shot being hit.

Jennifer Capriati blasts a shot during her victory over Elena Dementieva of Russia Monday at the U.S. Open.

The last time an entire day at the Open was rained out was Sept. 4, 1988.

Among the matches put off until today: top-ranked Andre Agassi against unseeded American Taylor Dent, and No. 5 Guillermo Coria against Jonas Bjorkman. The winners of those matches will meet in the quarterfinals.

Agassi complained after his third-round meeting with Yevgeny Kafelnikov was the only singles match postponed Saturday because of rain. Agassi was angered that the players weren’t consulted, and that Dent’s match against Fernando Gonzalez went on as scheduled. Now Agassi will have plenty of rest before facing Dent.

Capriati had time to relax Monday, even catching some Zs during one of the delays.

“When I want to sleep I can sleep,” she said. “I’m used to taking naps. I take a nap every day.”

Her match was slated to start at 12:45 p.m., but that was pushed back by an hour. Once they did get on the court, Capriati, a three-time major champion, and Dementieva, a 2000 Open semifinalist, were given 10 minutes to warm up, twice what’s normally allotted. And then they finally started, only to be ushered off the court at Arthur Ashe Stadium after 13 minutes — enough time for Capriati to go up 4-0.

A break of nearly 41/2 hours followed. Then they played another 36 minutes until sprinkles prompted the chair umpire to stop action, drawing boos from the few thousand fans in the stadium. Capriati led 6-2, 3-2.

After about another hour, play resumed.

The players immediately traded breaks of service, and then Capriati let Dementieva take a 5-4 lead in the second set by getting broken at love with an errant forehand.

Capriati straightened out her game in a hurry.

She broke back to 5-5, then held to 6-5 with help from her only ace (at 108 mph).