A LUCKY HOLE: Phil Mickelson's wife felt a wild shift of emotions on the par-3 seventh hole Saturday morning.

Standing to the right of the green, Amy Mickelson watched Chris DiMarco make only the second ace in Presidents Cup history, giving DiMarco and Mickelson the early lead in an alternate-shot match.

Moments later, she discovered that a sapphire had come loose from her ring and fallen into thick rough.

After the American team walked by toward the eighth tee, she started searching in the tall grass and soon was joined by a half-dozen marshals, and even a few fans pressed near the ropes. Right when she was about to give up, a marshal found the sapphire.

Mrs. Mickelson hugged him twice, asked for a business card and was all smiles again.

"This really was a lucky hole," she said.

By the way, DiMarco used a 7-iron to ace the 187-yard hole, which hugs the shoreline of Lake Manassas.

"You could see it in the air, like, 'OK, this is going to be good.' And you saw it bounce and you saw it roll," DiMarco said.

It was the fifth hole-in-one on the PGA TOUR in DiMarco's career. The only previous ace in the Presidents Cup was made by International player David Frost on the same course in 1994.

LET'S PLAY OVERTIME: To help avoid a repeat of the tie finish in the 2003 Presidents Cup, the rules will be different for Sunday's singles.

Any match that is even after 18 holes will go to a sudden-death playoff -- until one team or the other has reached the required 17½ points to win the Cup. Once the Cup is secured, all matches that are tied through 18 will be called a halve.

Of course, that doesn't mean there can't be a tie for the Cup. If each team wins six matches Sunday, there will be a 17-17 draw -- and the Cup will be shared for yet another two years. There will be no extra one-on-one playoff, as Tiger Woods and Ernie Els had two years ago in South Africa before darkness halted play.

Left unanswered is what happens if darkness stops play this time with the competition undecided.

"Darkness?" U.S.captain Jack Nicklaus said with a sigh. "You're going to have to ask a higher power. I don't have the answer to that question."

WRONG HOLE, TIGER: Tiger Woods and Jim Furyk went 1-0-1 in their two matches Saturday, but they also provided some comic relief at the short par-4 eighth.

Woods' tee shot went awry and landed at the No. 9 tee. Furyk's attempt to get the ball back to the correct hole failed -- his shot hit a tree branch, dropping the ball right back on the tee box. Woods got the ball to the steep rough by the eighth green, Furyk got the ball to the fringe, and Woods made one putt before the hole was mercifully conceded to Vijay Singh and Stuart Appleby.

POINTLESS PLAYERS: After three days, Americans David Toms and Kenny Perry are the only two players in the competition yet to score a point.