INCHEON - Confusion and controversy struck the Presidents Cup on Friday when Phil Mickelson and Zach Johnson lost the seventh hole "twice" after being penalised in a baffling rules infringement. The US pair stood on the seventh tee at the Jack Nicklaus Golf Club, Incheon, all square in their four-ball match against Aussie duo Adam Scott and Jason Day.

But by the time they walked off the green they were two holes down -- something that would seem impossible in match play golf. It turned out Mickelson had breached a little known match play rule which states you must play the entire round with the same brand and model of golf ball in fourballs and singles.

"I used a firmer Callaway that would go a little bit longer and try to get there in two," explained Mickelson. "Didn't really think much about it. But I was talking with Jay (Haas, US captain), and I just thought, 'Gosh, I'm going to ask. I'm sure it's not an issue'. Turned out it was an issue. Obviously as a player, you need to know that. You need to know the rules. The weird thing was I've never heard of a match adjustment penalty. I just thought I pick up, put the right ball in play the next hole. But obviously that was not what happened."

Johnson made a par five, but Day won the hole for the International team with a birdie four. Mark Russell, vice-president of rules and competition for the PGA Tour, told reporters why the unusual penalty had been imposed. "He breached the 'One-Ball Condition'," said Russell. "In this situation, the penalty for breach of this condition is a one-hole adjustment to the state of the match. The USA side lost the seventh hole, making the International side one up. At this point, the adjustment penalty of one hole is applied, resulting in the International side being two up through seven holes." In effect, the US 'lost' the hole twice. Russell admitted that Mickelson could have continued on the hole but was advised he was disqualified from it by the rules committee in discussion with the match referee Gary Young. "Okay. I accept total responsibility for that mistake," Russell said. He added he could not remember ever a situation where a pair lost two holes while playing only one. "I can't (remember that happening). We don't play fourball match play very often. You know, it's a strange situation." US captain Jay Haas said the issue was over. "It's just unfortunate that he was told he had to pick up the ball," Haas told reporters.

"Had he been able to play out and make a four and tie the hole, then it would only have been one down instead of two down. We talked to Mark Russell, and they (rules committee) acknowledged that it was their error, but again, there's nothing to be done."

The ruling had competitors, watching media and spectators alike scratching their heads. Golf fans and even professional golfers were quick to take to social media to criticise the game's plethora of obscure rules, which run to more than 600 pages, and can have marked differences between the usual professional stroke play format and match play seen in Presidents and Ryder Cups.

"How can you lose a hole twice???! #ussgarules #wow," tweeted former US team member Keegan Bradley.

One Twitter user, Ari Marcus, said: "So apparently you can lose a hole twice now... How can any match be closed out early now? I.E. How can you lose 2&1 if this is possible?" Another, Matt Blackly, tweeted: "Yet again the rules of golf are as clear as mud and destined to turn people away from the game! #Simplify it."