INCHEON, South Korea -- The International team wound up winning two holes in one at the Presidents Cup on Friday when Phil Mickelson didn't know the rules.
Mickelson was not aware of the one-ball condition for his four-ball match, switching to a different model to give him a better chance of reaching the par-5 seventh green. The rules committee made a mistake of its own to compound the error in a bizarre sequence of events
The result? Jason Day and Adam Scott went from all square to 2 up in just one hole.
Mickelson's mistake wound up costing the Americans a half-point when the match ended in a draw.
"It's a strange situation," said Mark Russell, the vice president of rules and competition for the PGA Tour.
With three wins and a half-point during Friday's four-ball matches, the International team cut the American lead to 5-4 going into a double session of eight matches on Saturday.
The one-ball condition means that players cannot switch golf ball models during the round. The penalty is known as a one-hole adjustment. So when Mickelson realized he was playing with a different ball, the International team was to be awarded one hole.
"The PGA of America doesn't have a one-ball rule," Mickelson told reporters at the Presidents Cup, referring to the organization that runs the PGA Championship and Ryder Cup when it is played in the United States. "You can play 18 different balls, brands, whatever, on 18 different holes during the PGA Championship and the Ryder Cup. So this threw me for a loop that we have a one-ball that we've never really had and I didn't think much about it.
"But it's my responsibility to know that. I should have at least asked about it before I teed off. It just had never been a thought for me as a player, but that's your job to know that."
Mickelson's mistake was then compounded.
Then, match referee Gary Young consulted with the rules committee, and Russell said he told him that Mickelson was disqualified from the hole. Russell said he checked with other officials on the committee and they concurred. Only later did they realize Mickelson should have been allowed to complete the hole.
Day won it with a birdie to go 1 up over Mickelson and Zach Johnson, and it became 2 up because of the one-hole adjustment.
Mickelson didn't think anything of the rule when he put a different ball in play, mainly because there is no one-ball rule at the PGA Championship or the Ryder Cup when it is held in America. Only when he was walking down the seventh fairway and saw U.S. captain Jay Haas did he think to ask.
"I was talking with Jay and I just thought, 'Gosh, I'm going to ask. I'm sure it's not an issue,' " Mickelson said. "And it turns out that there was a one-ball rule and it was an issue. As a player, you need to know that. You need to know the rules, and if you have a question, you do it beforehand."
"The weird thing was I've never heard of a match adjustment penalty," he said. "I just thought, 'OK, if I hit the wrong ball, no big deal. Zach will cover me on this hole.' But obviously, that's not what happened."
Russell said once a shot had been played, the committee could not go back and have Mickelson finish the hole because "allowing a correction could potentially undermine the strategy" already in play by both teams.
"It's just unfortunate that he was told he had to pick up the ball," Haas said. "Had he been able to play out and make a 4 and tie the hole, then it would only have been 1 down instead of 2 down. But that didn't happen, so nothing you can do about it."
The mistake by Mickelson was not knowing the rules. The mistake by the rules committee was not letting him finish the hole.
"Phil made a mistake. It's unfortunate that they didn't immediately say that he could have played out the hole," Haas said. "But that happens. Phil made a huge mental error, and then they compounded it a little bit. But if he hadn't been speeding, he wouldn't have gotten a ticket. So I don't have a problem with it."
The International team also picked up wins from Louis Oosthuizen and Branden Grace and from Thongchai Jaidee and Charl Schwartzel.
The Associated Press contributed to this report.