World No 1 Scottie Scheffler and Sam Burns rallied late to give the United States a 3-2 lead over the Internationals after Thursday's opening four-ball matches at the Presidents Cup.
In the marquee opening-day matchup at Medinah, Scheffler and Burns edged South Korean Im Sung-jae and Australian Min Woo Lee 1-up to take a slender US lead in a tournament it traditionally dominates.
Im made a 10-foot birdie putt to win the par-3 13th hole, but a Burns tap-in birdie on 14 lifted the US duo back to even. Scheffler won the 17th with a par and tied the 18th with a par for the victory.
"We just did our best to stay in it," Scheffler said. "We stepped up when we needed to."
"I'm really proud of them. So happy for Scottie and Sam to get that big lead-off win for us," added US team captain Brandt Snedeker.
While Scheffler's match was first to tee off, Justin Thomas and 21-year-old rookie Jackson Koivun bagged the first point of the 16th Presidents Cup.
They defeated Canada's Corey Conners and Colombia's Nico Echavarria 4&3.
The Americans never trailed, with Thomas winning the fifth hole on a 22-foot birdie putt for a 2-up edge, then making birdie from 12 feet to win the 14th and 16 feet to win the 15th and clinch a win.
The two-time major winner improved to 7-0 in Presidents Cup four-ball matches.
"Match play is such a bizarre thing," Thomas said. "I've played great with some great partners. Happy we got a point today."
The Internationals equalized when Japan's Hideki Matsuyama and Ryo Hisatsune defeated Cameron Young and Xander Schauffele 3&1.
Matsuyama gave the Japanese duo the lead for good by winning the eighth on a six-foot par putt to 1-up and ninth on a birdie from just inside 10 feet for a 2-up edge.
He halved the next five holes with pars or better, then won the match with a 10-foot birdie putt at 17.
"He played well and I did the best I could. I was just happy to get the point," Matsuyama said through a translator.
'ACCELERATOR'
After Scheffler and Burns had made it 2-1, Wyndham Clark and Collin Morikawa added a further US victory, going 3-up within six holes against New Zealand's Ryan Fox and Australian Adam Scott.
Fox hit back with a birdie on seven, but Clark immediately responded with an 18-foot birdie putt on the eighth.
Scott birdied the par-three 13th to again reduce the gap back to two, before a Clark birdie on 15 prompted a 3&2 win.
The day's final match pitted South Koreans Tom Kim and Kim Si-woo against Chris Gotterup and Patrick Cantlay.
The Korean duo never trailed, winning the first two holes.
Tom Kim nearly had a walk-off ace on the par-three 16th. The ball ricocheted off the flagstick, but his birdie was still enough to seal a 3&2 win.
"We had to put the accelerator down. We kept the pressure on and played well," he said.
The United States has a 13-1-1 edge in the rivalry with the Internationals.
The non-European global squad's only victory came in 1998 at Australia, and the US is seeking an 11th consecutive victory in the biennial competition.
International captain Geoff Ogilvy said the 3-2 deficit was "not that bad."
Teams need 15.5 of the 30 points on offer to capture the trophy.
"Saw some good stuff... We will take that," said Ogilvy.