Shinnecock Hills is proving to be a brutal course in the opening round of the 2018 US Open, and few players have had more trouble with it than Rory McIlroy, Jason Day and Jordan Spieth. Three of the world’s top eight golfers, they all carded scores of 8-over or worse over their first 18 holes.

McIlroy trails the group after an ugly 10-over 80, followed by Day at 9-over 79 and Spieth at 8-over 78.

It’s hard to blame any of them too much, however. Scott Piercy and Ian Poulter (both 1-under) are the only players to finish their rounds under par so far. This is sizing up to be one of the most testing US Open courses in years.

Trouble started for McIlroy, who set the US Open record for lowest four-round score (268) in 2011, early on Thursday. He started on the back nine with a par on the 10th, then posted back-to-back bogeys followed by consecutive double bogeys.

By the end of his fifth hole, McIlroy was already 6-over. He responded with a birdie at the 15th to end the bleeding, but it wouldn’t last long. He bogeyed the 16th and 18th holes, then opened the front nine with another double bogey and a bogey.

Day similarly ran into issues starting on his second hole. He bogeyed the second through fourth holes, then added two more bogeys to hit the turn at 5-over. The back nine didn’t go much better.

Spieth’s unfortunate start included a double bogey on the seventh hole and a triple bogey on the par-3 11th. He birdied the 18th to get one back, but like with McIlroy, it was too little, too late Thursday.

McIlroy, Day and Spieth may have had the worst time, but they’re not the only big names being battered around by Shinnecock Hills. Phil Mickelson and Bubba Watson finished 7-over. One player, England’s Scott Gregory, posted a 22-over 92. This course has been eating players alive with powerful winds and treacherous greens.

The US Open is often known for its difficult courses. This one is definitely giving the world’s best a challenge. You can check out a full leaderboard from the 2018 US Open here.