CALIFORNIA - SOUTH Korea's KJ Choi sank a three-foot putt for a birdie and US$75,000 (S$113,535) at the third hole on Saturday to come away the biggest winner on the first day of the Skins Game.

Phil Mickelson bagged US$25,000 with an eagle on the fourth hole, while Canadian Stephen Ames and US Open runner-up Rocco Mediate were shut out on the opening day's nine holes of the two-day, 18-hole unofficial golf event.

After Choi and Mickelson's wins, the quartet halved the next five holes, so that US$900,000 of the tournament's one million-dollar purse will still be up for grabs on Sunday.

In the four-man tournament, players compete for money at each hole rather than the low score for the round.

A player must win a hole outright to win a skin. If a hole is tied, the skin and money carry over to the next hole.

Sunday's opening 10th hole will be worth 250,000 dollars.

Ames, the two-time defending champion, and Mediate halved the opening hole, and Mediate and Choi halved the second hole, so that Choi's winning birdie at the par-four third was worth three 25,000-dollar skins.