Tiger Woods insisted the Presidents Cup is far from over after the United States were dominated by the Internationals at Royal Melbourne Golf Club.
Winners of the past seven Presidents Cups, defending champions the USA only managed one point as the Internationals claimed a 4-1 lead following day one in Melbourne on Thursday.
Captain Woods opened the four-ball contests alongside Justin Thomas and led the USA to a comprehensive win against Marc Leishman and Joaquin Niemann.
Woods produced a masterclass with six individual birdies as the USA drew first blood before Ernie Els' Internationals won the remaining four matchups.
It was a dream start for the International team, who have not claimed the Presidents Cup trophy since 1998.
But Woods told reporters in a news conference: "Well, this is a long four days. I mean, we have to go earn this Cup.
"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. The guys will regroup and we'll come out tomorrow ready to go."
Woods and the USA have made changes for Friday's foursomes, with Rickie Fowler and Matt Kuchar coming in for Bryson DeChambeau and Tony Finau.
Kuchar and Dustin Johnson will open proceedings against Louis Oosthuizen and Adam Scott, while Fowler is set to team up with Gary Woodland for the Im Sung-jae/Cameron Smith battle.
Woods will continue his partnership with Thomas as Byeong Hun An and Hideki Matsuyama await, Patrick Reed and Webb Simpson take on Leishman and Abraham Ancer, and Xander Schauffele and Patrick Cantlay face Niemann and Adam Hadwin.
"We're excited about getting out there tomorrow and winning some matches, and turning this thing around," 15-time major champion Woods said.
"We've got an amazing lay-up going out there tomorrow, and the guys are all fired up and ready to go."