And if not for U.S. captain Jack Nicklaus, it might have been worse.

Despite a leaderboard covered with American red numbers, perhaps the most poignant moment of a gray afternoon was Nicklaus instructing Phil Mickelson and Woody Austin to concede a 3›-foot par putt on the 18th hole that assured Mike Weir of Canada and his International team its only point of the opening session.

In a tense battle with only six holes halved, the match was all square going to the 18th when both sides missed the green. Mickelson blasted out to 12 feet, while Weir chipped to 3 1/2 feet above the hole. Austin made the par putt, and before Vijay Singh spot his ball, the match was conceded.

"Captain Nicklaus was right. It was the right thing to do," Mickelson said.

It was typical of Nicklaus, who famously conceded a putt about the same distance to Tony Jacklin in the 1969 Ryder Cup that allowed those matches to end in a draw. That gesture became a symbol of sportsmanship in match play between countries and continents.

Then again, this was only Thursday — and it was clear the Americans were in charge.

The matches began 30 minutes late because of a downpour on the Ile Bizard, and once they began, the Americans wasted no time taking control. Steve Stricker, returning to the Presidents Cup after an 11-year absence, joined with rookie Hunter Mahan for a 3-and-2 victory over the Australian pair of Adam Scott and Geoff Ogilvy.

Tiger Woods and Charles Howell III were in the final match and picked up a 3-and-1 victory over K.J. Choi and Nick O'Hern, with Woods doing most of the heavy lifting and Howell coming up with big putts on the back nine.

It was the biggest blowout in the opening session since the Americans pitched a 5-0 shutout in 2000.