Jason Day withdrew from the U.S. Open after 10 holes on Thursday in Southampton, N.Y., citing a back injury.
The Australian played the back nine of Shinnecock Hills Golf Club to begin his round and went 7 over, including six straight bogeys at Nos. 13-18. He then grimaced in pain after taking a swing at the first tee box.
Day finished the hole but then summoned a cart to drive him back to the clubhouse. He was playing in his 14th U.S. Open.
Day, 38, is best known for winning the 2015 PGA Championship and holding the No. 1 world ranking for 51 weeks. He had made the cut in each of the first two majors this season, tying for 12th at the Masters.
He has dealt with back pain throughout his career. Day also collapsed while playing a round at the 2015 U.S. Open due to vertigo but was able to finish the championship.
Day finished second in the 2011 U.S. Open and tied for second in 2013.
