San Francisco Frontiers - Ryder Cup begins in electric atmosphere at Bethpage Black

US President Donald Trump was among 50,000 spectators expected for the opening day as the Americans and Europeans renewed golf hostilities for the 45th time in the biennial rivalry.

Rahm's first shot went well into the right rough while DeChambeau smashed his ball into the fairway 10 yards shy of the green at the first hole, to the delight of the crowd.

Trophy holders Europe seek the first road triumph by either side since their 2012 "Miracle at Medinah" while the Americans try to win back the Cup after losing two years ago in Rome.

US fans chanted "We want Bryson" in the high-pressure crucible of the first tee, with 5,000 fans watching from the largest grandstand in Ryder Cup history, creating an intense scene from the start.

"The first tee, first match, wherever you play home or away, it's intense and pure energy," Europe captain Luke Donald said.

Americans DeChambeau and Justin Thomas faced Europe's Jon Rahm and Tyrrell Hatton in the first of four foursomes (alternate shot) matches to begin the day, with four four-ball (best ball) matches set for the afternoon.

"We've got a big responsibility and role. We're going to be going up against a great team," DeChambeau said. "They're a formidable force, but we want to send a message."

US captain Keegan Bradley wants to excite the home supporters from the start with two-time major winners DeChambeau and Thomas, draped in an American flag as they walked out to huge roars from US fans.

"They are both fiery players," said Bradley. "They are both relishing the opportunity to lead out our team. They are just two guys that thrive in that role."

When the main gates opened under pitch black skies at 5 am (0900 GMT), hundreds of fans stampeded along a floodlight-illuminated path to the main grandstands at the first tee, a race with passion worthy of any Olympic distance event, to grab a coveted spot for the opening spectacle.

American fans -- clad in red, white and blue -- chanted "U-S-A" and Europe supporters, wearing blue and yellow, sang out, "Ole, Ole, Ole," to stir the excitement and tighten the nerves for the first shots by some of golf's biggest stars.

Extra security measures were in place for Trump's appearance. Details have not been revealed but a source told AFP plans have been made for the afternoon.

Top-ranked Scottie Scheffler, whose six wins this year include the British Open and PGA Championship, and world number three Russell Henley were in the second foursomes match for the Americans against Europe's Matt Fitzpatrick and Ludvig Aberg.

World number two Rory McIlroy, who won the Masters in April to complete a career Grand Slam, joined Tommy Fleetwood for Europe in match three against Collin Morikawa and Harris English.

The morning session's final match saw Americans Xander Schauffele and Patrick Cantlay pitted against Europe's Robert MacIntyre and Viktor Hovland.

- Aggressiveness is good -

"Aggressiveness is probably going to be a good strategy," Hovland said. "You're going to have to play like you're trying to birdie almost every hole."

The format features four morning foursomes matches and four afternoon four-ball matches on Friday and Saturday with 12 concluding Sunday singles matches.

The Americans will need 14.5 points to win the Cup. Europe, winners in 10 of the past 14 meetings, need only 14 of 28 points to retain the trophy.

The US team leads the all-time rivalry 27-15 with two drawn, but Europe lead 12-9 with one drawn since their team was expanded beyond Britain and Ireland in 1979.

L.Nguyen--SFF