PLAINFIELD, N.J., JULY 27 -- The U.S. Women's Open has become the tournament that will not end, but then, who wants it to?

Long-driver Laura Davies of England has tried to club it into submission, Ayako Okamoto of Japan has attempted to sharpshoot it out of its misery, and today Hall of Famer JoAnne Carner almost shocked it to death by moving into a tie for the lead at the age of 48 with a round of 3 under par, 69.

And still the Open goes on, for Carner, Okamoto and Davies will return Tuesday to Plainfield Country Club for an 18-hole playoff tied at 3-under-par 285, making this the most days an Open has covered in U.S. Golf Association history.

Thanks to thunderstorms that prevented the fourth round from being played Sunday and the tie after today's round, the tournament is heading into its sixth day -- but don't expect a full week out of this event. If the score is still tied after Tuesday's 18 holes, the players will head back to hole No. 1 for a sudden-death playoff.

Surprises have been abundant, including the withdrawal of defending champion Jane Geddes early this morning, officially because of back pain. She also was suffering from a score of 7-over-par 223 for three rounds. But nothing was as astonishing as the performance of Carner, who came from three strokes back at the beginning of the day.

Carner almost became the oldest Open winner ever when she birdied the par-5 No. 17 hole to take a one-stroke lead over Okamoto and Davies. But she bogeyed the 18th with three putts from 20 feet and missed the 68 that would have won it all and would have broken the women's competitive course record set by Bonnie Lauer and Dot Germain in the first round.

Okamoto and Davies, playing two holes behind her, parred safely in. Okamoto carded 72, including a startling double bogey, and Davies a steady 71 that included nine pars on the back nine.

"I think it's great," Carner said. "It's got a little of everything."

Three generations of players will engage in what amounts to match play across the 6,284-yard course designed by Donald Ross.

Davies is 23 and playing in just her third LPGA tournament. Okamoto, at 36, is seeking her first major despite winning three tournaments this year and becoming the third-leading money winner.

Then comes Carner, who at 48 would be the oldest Women's Open winner by eight years. Fay Crocker was 40 when she won in 1955. Even Ray Floyd was a babe in comparison when he won the 1986 men's Open at 43. Carner's second and most recent Open victory came 11 years ago when she defeated Sandra Palmer in a memorable playoff. Her last tour victory came in 1985.

Starting out today, Carner was lurking, but appeared an aging long shot at par, while Davies, though trailing by a stroke at 2 under, was considered too young and too likely to unravel. That left it to Okamoto, who began the day as the leader at 3 under and quickly added birdie putts of 25 feet at the second hole and 10 feet at the third. But Okamoto's round included just two more birdies, with two bogeys and a disastrous double bogey when her putting failed on the difficult par-4 ninth.

That put her into a tie she never escaped despite a birdie on the 10th hole, which she promptly gave back by three-putting from just three feet on the 13th.

"When I started, my heart was thumping, from the first to the 13th," she said through an interpreter. "I was tense and nervous. The double bogey on nine was a shock. Then I got the birdie on 10 and thought, if I was patient, I could hang in. It was a very difficult day."

Davies complicated matters by refusing to succumb to nerves. She posted three birdies and two bogeys on the front nine, and parred the entire back nine, including a marvelous save on the 18th when she got down with two putts from 60 feet, including a four-footer to make the playoff.

Her birdies came at the fourth with a 10-foot putt, at the par-5 seventh with a downhill 20-footer, and at the dramatic ninth where she hit a wedge to four feet and Okamoto double-bogeyed.

"I can't believe what happened," Davies said. "I came here with good expectations, but nothing like this."

Davies is mainly known on the LPGA tour for shooting a 66 to lead the first round of last year's Open in Dayton, Ohio. But she has five victories abroad, including last year's British Open, which she is scheduled to defend later this week. Her travel plans, however, have been considerably complicated. She will not arrive in England until 8 a.m. Wednesday, and has a five-hour drive to Cornwall, where she will tee off without a practice round.

"I think this is worth staying for," she said.

Davies is in the playoff largely on the merit of the ninth hole. She watched Okamoto hit a 5-wood on the 362-yard hole that at first appeared to be a good shot. But it spun off the edge of the green and into the apron, and from there she punched it out with her putter 10 feet past the hole. Her return putt ran by again by three feet, and the bogey putt just lipped out.

"When I hit the third one, I thought I might five-putt," Okamoto said.

Davies watched the agonizing process from the side of the green, then tapped in her four-footer, to tie at 3 under.

But that was only the beginning of the drama, for Carner had quietly crept within a stroke. She birdied the par-4 first with an 8-iron to six feet, and the par-4 fourth with a 6-iron to four feet. She then settled in for a long afternoon, posting 10 straight pars until the 15th, where she hit an 8-iron to five feet and knocked it in to finally go 3 under.

There was pure and simple pandemonium on the 493-yard 17th, a par 5, when Carner hit a wedge that eased to within four feet. She birdied it and listened to the crowd. "They were rooting me on from the start. I was pumped," she said.

But on 18, her 6-iron flew to the back fringe, and her 20-foot putt was a difficult downhill affair. She misread it and the ball rolled 10 feet past the hole. Her par attempt came within inches, but did not drop. "I blew it," she said. "I hit a pretty good second putt, but a spike mark killed it."