NEW YORK (AP) - Venus Williams, as wild as the weather in a first-set fiasco, escaped an upset Sunday at the U.S. Open after Mary Joe Fernandez strained a leg muscle skidding on a slippery court.

A rainy, blustery fringe of tropical storm Dennis delayed the start of play, interrupted every afternoon match and caused the postponement of eight doubles matches.

No. 1 Martina Hingis and No. 10 Arantxa Sanchez-Vicario saw their day match pushed back to the night session. Hingis extended her dominance over the Spaniard, beating her for the 12th time in 13 meetings, 6-4, 7-5, to reach the quarters.

The worst effect of the weather came from a light sprinkle that hit early in the second set of the Williams-Fernandez match and totally changed the outcome.

Williams, seeded No. 3, reached the quarterfinals with a 2-6, 6-1, 6-0 victory that stemmed entirely from a fall by Fernandez when she slipped on a wet spot chasing a shot behind the baseline.

Fernandez served superbly and broke an erratic Williams three times in the first set but was never the same after falling in the third game of the second set and straining the quadriceps muscle in her right leg.

Play was suspended at that point for about an hour and a half, and Fernandez was able to use the time to receive treatment from a trainer. Fernandez returned with her upper right leg wrapped, but her movement clearly was limited as she ran more slowly and played more tentatively. She managed to hold serve to 3-1, but lost the next nine games as Williams picked up her own game.

``It was definitely related to the rain,'' Fernandez said. ``It started to sprinkle and the court gets very, very slippery right away. My foot just slid.''

Fernandez hadn't wanted to stop at the time, but in hindsight wished that she had said something to the umpire about halting play when the rain started to fall.

``I should have,'' she said. ``I didn't.''

The rain had interrupted the match earlier, with Fernandez leading the first set 5-1.

``It was kind of the same thing,'' Fernandez said. ``I dragged my foot a little bit on the court, saw that it was kind of slick. I asked and we stopped. But once you get started, you want to keep playing. I thought maybe it's going to stop. But it was too slippery.''

As soon as Fernandez went down, Williams came around the net to see how she was.

``She was cute,'' Fernandez said. ``She calls me Mary, not Mary Joe. She's, like, `I'm sorry, Mary. Are you OK, Mary?' I looked at her, like, `Nooo, but I'll be OK.' But it was really nice of her to come and check up to make sure I was OK.''

``That was terrible,'' Williams said of Fernandez' fall. ``She had a really bad injury, and she just came off of a wrist injury.''

Williams had reached the fourth round without striking a ball when another opponent, Henrieta Nagyova of Slovakia, pulled out with a wrist injury.

``It was difficult,'' Williams said. ``I haven't played singles since Wednesday. All those days off and the rain really hurt. She was pinpointing her shots.

``I was producing quite a few short balls which gave her the opportunity to look like an All-American. I looked like the last NFL pick.''

Williams said she's confident she can raise the level of her tennis in the next match. But she wishes she wouldn't have to.

``I shouldn't be raising the level of my game,'' she said. ``I should be playing wonderful tennis throughout this next week.''

In the only other women's matches completed Sunday afternoon, Anke Huber continued her comeback from injury to knock off Australian Open finalist and No. 15 seed Amelie Mauresmo 6-4, 6-4, and No. 12 Barbara Schett beat Elena Likhovtseva 6-0, 6-1.

Huber held double-match point at 6-4, 5-3, 15-40 on Mauresmo's serve when rain interrupted play. When they resumed, Huber made four consecutive errors to allow Mauresmo to hold serve. Huber quickly regrouped, though, and held at love to put away the match.

On the men's side, No. 7 Todd Martin advanced to the fourth round when Magnus Larsson retired with a knee injury after dropping the first set 6-3, and No. 9 Greg Rusedski beat Chris Woodruff 7-5, 3-6, 6-3, 6-4.

Larsson became the fifth man to quit in mid-match in a tournament already depleted by the injuries to four-time champion Pete Sampras and 1998 runner-up Mark Philippoussis.

In the evening, Frenchman Fabrice Santoro became the sixth man to exit with an injury in a match, curiously quitting with two points to go at 6-1, 6-0, 5-1, 0-30 on his serve against Jiri Novak. Santoro blamed a sore ankle, but he walked away without a limp.

Larsson stopped because of tendinitis in his left knee that has been hurting for several days and may have been aggravated by playing and practicing a lot on hardcourts for the past six weeks.

``It's painful as soon as I put the weight on my left foot,'' Larsson said. ``It goes up to just under the knee. It's real tender on one spot.''

Martin said he'd been told by a friend before the match that Larsson had trouble getting around the court in his previous match Friday, but didn't think he was in such bad shape that he had to retire after one set.

``When he came up to shake my hand, I was a little surprised because when someone is really ailing it's usually a bit more one-sided than one sort of squeaky break,'' Martin said. ``Pain's one thing, but when you lose the strength, that's another. Today was probably the first experience this week for him to lose strength rather than just experience some pain.''