Dustin Johnson withdraws from Masters with back injury

Dustin Johnson and Brooks Koepka walk on the 13th hole during a practice round for the Masters golf tournament Wednesday, April 5, 2017, in Augusta, Ga. (AP Photo/Charlie Riedel) (The Associated Press)

Dustin Johnson hits to the 11th hole during a practice round for the Masters golf tournament Wednesday, April 5, 2017, in Augusta, Ga. (AP Photo/Charlie Riedel) (The Associated Press)

FILE - In this March 26, 2017, file photo, Dustin Johnson is shown after a birdie putt on the sixth hole during semifinal play at the Dell Technologies Match Play golf tournament at Austin County Club in Austin, Texas. The world's No. 1-ranked player was forced to withdraw from the Masters on Thursday, April 6, 2017, because of a lower back injury suffered less than 24 hours earlier in a freak fall at the home he was renting for the week.(AP Photo/Eric Gay, File) (The Associated Press)

Dustin Johnson has withdrawn from the Masters after injuring his lower back in a fall at the home he was renting for the week.

The world's No. 1-ranked player arrived at Augusta National on quite a roll, having won his last three starts.

But he never took a shot at the first major championship of the year.

Johnson walked to the first hole Thursday, as if he was going to play in the final group of the day, but changed his mind at the last possible moment. Bubba Watson and Jimmy Walker teed off while Johnson sauntered back to the clubhouse, a stunning start to the tournament.

His Masters was over before it ever began.

Johnson was injured late Wednesday afternoon when he took what his agent described as a "serious" fall down a staircase.