SAN FRANCISCO (AP) — One putt changed everything except the lead Thursday in the Presidents Cup.The Americans were poised to seize control in the opening session of foursomes at Harding Park, already assured of the lead and on the verge of winning the final match for a two-point advantage.Justin Leonard had a 3-foot birdie putt to win a putt he first thought had been conceded and was stunned when the putt caught the right edge of the cup and spun away.The match was halved, and the Americans had to settle for a 3 1/2-2 1/2 advantage.”We wanted to get out of the day with pretty close to a push, and I‘m very, very happy,” International captain Greg Norman said.He was fortunate for that.Tiger Woods and Steve Stricker were dominant from the start, playing bogey-free in the difficult alternate-shot format and teaming up for six birdies in a 6-and-4 victory over Geoff Ogilvy and 18-year-old Ryo Ishikawa.Phil Mickelson and Anthony Kim came to life late, closing with four straight birdies to give the Americans the first point of the matches with a 3-and-2 victory over Mike Weir and Tim Clark.The momentum switched to American red on the scoreboard late on the cloudy, cool afternoon on this public course south of San Francisco. The final push figured to come from Leonard and Jim Furyk, who made a furious rally in the middle of the match and surged ahead of Retief Goosen and Y.E. Yang, 2 up with two holes to play.Goosen holed a birdie putt on the 17th to send the match to the par-5 18th, and the South African missed the green to the right. Leonard hit a splendid fairway metal to the middle of the green, setting up what appeared to be a two-putt birdie.Furyk lagged to 3 feet, the International team got up-and-down for birdie, and Goosen looked over at Furyk as if wondering why Leonard even needed to putt. Eventually, the South African realized the putt meant something.Did it ever.The Americans were ready to celebrate another point. The International team was prepared for another big deficit.”I just hit a bad putt,” Leonard said. “I knew I was going to need to make that little putt. Unfortunately, I missed it.”Norman said there was no gamesmanship on Goosen‘s part.”He thought the match was over,” Norman said. “He didn‘t concede the putt, he just thought the match was over. It was a legitimate mistake, and no intent or malice. It was just the intensity of the game.”Next up are six more matches today, this time fourballs.Two years ago, the International team failed to win a match in the opening session and fell five points behind. This is one time a tie the halve in the final match felt far better. It goes into the second round with a fighting chance.—–Contact The Daily Reveille’s sports staff at [email protected]