“It was very exciting right down to the last putt,” USA captain Jim Hyler said. “I’m so thrilled for these three young men, they played really hard all four days. We had different people count each day and it is a team event and I think the way it worked out for us really highlights what a great team event it is.”

The Americans won with a record score of 38-under-par 534, eclipsing the 554 total of the Netherlands in 2006 by 20 strokes.

Canada won the silver medal, two strokes behind the USA at 536 and Spain, fueled by the lowest individual score in history by Jon Rahm, won the bronze medal at 537.

McCarthy was 8-under through eight holes and set the WATC mark for lowest nine-hole score when he made the turn in 28. He was the only member of the gold-medal team to record all four scores in the 60s. Beau Hossler, the 2014 Western Amateur champion, posted a non-counting 75 for the USA in the fourth round.

“I knew my score was counting for sure so my game plan on the back nine was to not do anything stupid or crazy and not drop any shots,” said McCarthy, a senior All-American at the University of Virginina. “At the same time I still needed to be aggressive and give myself chances because he (playing competitor Adam Svensson) was making birdies and I knew he was going to count for Canada.”

Canada, which began the day six strokes behind the USA, used a 7-under 65 from Barry University All-American Svensson and a 4-under 68 from 2014 U.S. Amateur runner-up Corey Conners for team total of 133.

The championship was tied at 37 under par when DeChambeau and Conners, playing in the last group, reached the 18th tee at the par-72 Iriyama Course.

Both players hit their drives in the fairway on the 443-yard, par-4. DeChambeau, who shot 61, the lowest round in history in the third round, played first and hit a 50-degree wedge from 110 yards. Conners’ approach settled 35 feet from the hole on the back collar.

"I didn't know about the scores and I wasn't sure if his would be counting or not,” Conners said. “There was never a doubt that he was going to make it. It was a pretty nice looking putt."

Conners left his birdie attempt short, which set the stage for DeChambeau’s winning birdie.

“I knew where we stood when I was on the l8th tee box and I knew that I needed a birdie on the last,” said DeChambeau, an All-American at Southern Methodist University, “I striped my drive and hit a wedge in there and nailed that nine-footer. I said that I needed to make birdie and I went out and made birdie”

"We fought back really hard today,” said Canadian captain Graham Hill. “We knew that we were going to have to play well to have a chance and we played great and brought it right to the last hole. Obviously, it didn't work out the way that we wanted but we're really proud of the guys for the way they played and the way they handled themselves. It's a good finish for us, disappointing not to win but we're happy with it."

Sweden was fourth at 538; Argentina was fifth at 539; Australia, England and France were tied for sixth at 540; Scotland was ninth at 542 and Switzerland was 10th at 544. Japan, the host team, finished tied for 29th.

The previous mark for low individual score for 72 holes was held by golf legend Jack Nicklaus, who shot 269 in 1960. Rahm’s four rounds were 70-64-62-67 for 23-under-par 263

“I’m about ready to cry right now because, honestly, Jack Nicklaus is a hero,” said Rahm, an All-American at Arizona State. “I can’t really explain how good it feels to beat his record. It’s just unbelievable.”

The USA, which also won in Turkey in 2012, has now recorded 27 top five finishes in 29 Eisenhower Trophy competitions.

“There’s personal achievements that we’ve all had but it’s in a different league to play for your country and represent your country well,” said Hossler, who posted counting scores of 68 and 66 in the first two rounds. “We’re very proud of what we’ve done this week. Denny and Bryson played incredibly these last two days and for me to reap the benefits of that is nice. I struggled today but it’s definitely an honor to represent your country and get a W.”

Forty-two of the 67 teams posted 72-hole totals that were under par.

The World Amateur Team Championship is a biennial international amateur competition conducted by the International Golf Federation (IGF), which comprises 137 national governing bodies in 131 countries. The competition, which is being held for the 26th time, is rotated among three geographic zones: Asia-Pacific, Americas and Europe-Africa.

This year’s event is hosted by the Japan Golf Association. The teams play for the Eisenhower Trophy. The IGF is the international federation for golf for the International Olympic Committee and will conduct the Olympic golf competition in Rio de Janeiro in 2016. In each round, the total of the two lowest scores from each team constitutes the team score for the round. The four-day (72-hole) total is the team’s score for the championship.