Southampton, United States: Jason Day, the 2015 PGA Championship winner, withdrew from the 126th US Open in Thursday's first round due to a back injury.
The 38-year-old Australian, who has been nagged by back injuries for years, had just completed the back nine to begin his round when he suffered the setback on a practice swing at the first hole.
Day had been playing alongside two-time major winner Collin Morikawa of the United States and England's Aaron Rai, who won last month's PGA Championship.
Day had his best US Open finish, a solo runner-up effort, in 2011 in his debut in the event.
The Aussie star has won 13 PGA Tour titles, the most recent in 2023 at the Byron Nelson tournament.