What was the toughest hole in Round 1 at the U.S. Open at Oakmont?

For some, the ninth hole was the finishing hole Thursday — a welcomed end to a steamy day at the 125th U.S. Open championship at Oakmont Country Club.

For others, it was a chance to make the turn on a high note before playing the back nine.

Turns out, no matter when it was played, No. 9 was just plain hard.

It features a blind tee shot and steep uphill approach with a ditch to left and bunkers along the right of the fairway. The hole plays as a par 5 for members but as a par 4 during championships.

Statistically, it was the hardest hole on the course in Round 1. A 463-yard par 4, it averaged 4.57 strokes, with just eight birdies.

There were 74 pars, as well as 58 bogeys and 14 double bogeys.

During the 2016 U.S. Open, No. 1 played as the hardest hole. On Thursday, the first hole played as the 11th toughest hole with an eagle, 15 birdies, 93 pars, 41 bogeys and five doubles.

On the other side, the easiest hole on Thursday was the 621-yard par 5 fourth, where Patrick Reed had an albatross (double eagle).

No. 4, which is the longest hole on the course, saw 4 eagles or better, 43 birdies, 74 pars, 32 bogeys and three double bogeys.

In 2016, the easiest hole was No. 17. On Thursday, No. 17 was the second easiest hole that featured 43 birdies as players regularly attacked the green from the tee on the reachable par 4 that played 327 yards.