Royal Melbourne is hosting the 13th edition of the competition, with the Internationals having triumphed just once before, in 1998 (also at Royal Melbourne), with a tie in 2003.

Tiger Woods is player-captain of the US, and his pairing with Justin Thomas delivered the first point of the day, winning 4&3 over Australia's Marc Leishman and Chile's Joaquin Niemann.

But that was as good as it got for the favourites, as the International team, captained by South African Ernie Els, hit back after going 1-0 down.

His compatriot Louis Oosthuizen and Abraham Ancer from Mexico took out Dustin Johnson and Gary Woodland, also 4&3.

Australian Adam Scott was inspired by the home crowd alongside South Korea's An Beyong-hun, pulling off a surprise win over Bryson DeChambeau and Tony Finau.

The battle between duo Adam Hadwin of Canada and South Korean Im Sung-jae and Xander Schauffele and Patrick Cantlay went right to the wire, with the Internationals winning 1-up.

American Patrick Reed also had a chance to get something from his partnership with Webb Simpson, but missed a putt on the 18th to hand Japan's Hideki Matsuyama and CT Pan of Chinese Taipei the victory.  

"This is an unbelievable start," Els said.

"We haven't had a start like this for many years."

Woods, who is only the second playing-captain in the history of the event, is confident the US can turn things around.

"Just because we lost the session doesn't mean the Cup's over - there's a long way to go, a lot of points available," he said.

"The guys will regroup and we'll come out tomorrow ready to go."

It would be a major embarrassment for Woods if they do miss out on a trophy they've effectively owned since 1998, with day two's five foursome matches now taking on huge significance.