"It all started out with that first day. I made that hole-in-one and all of a sudden I felt like I could make some birdies. I haven't had that feeling for a while," said Johnson, who had struggled the last few years on tour.
Johnson birdied three of his last four holes Sunday to shoot 6-under par 64 and win the U. S. Bank Championship by a stroke over Ken Duke. He finished 16-under par on the 6,759-yard Brown Deer Park Golf Course to win the $720,000 first prize.
Johnson, the sixth golfer from Sweden to win on tour and seventh first-time winner this season, had to go through qualifying school last fall to get his tour card back and he had only made the cut in three of ten events this season before coming here.
His ace linked him with Tiger Woods, who was the last player to make a hole-in-one there in his professional debut in 1996.
Johnson got the birdies when he needed them the most, first sinking a birdie putt of about 12 feet on the par-4 17th-hole to break away from a tie with Duke at 14-under. He then birdied the par-5 18th from less than 2 feet.
The birdie putt came after Johnson hit a great second shot to reach the green.
"I hit a three wood just straight at the pin and it rolled up to 20 feet and I two-putted for birdie," he said.
That final birdie was vital to his victory because Duke, playing in his threesome, also birdied the final hole.
Duke, who shot a 5-under 65, birdied the hole even though his second shot landed in a greenside bunker. It was a disappointing finish because Duke has never won a tournament, but he felt good that he stayed with Johnson to the end.
"I holed a couple of putts on him early, but he holed a couple back on me," Duke said. "I had a great week. Shoot 5-under on Sunday and just get beat by one. You got to take your hat off to him."
Dean Wilson (65), Chad Campbell (65) and Chris Riley (66) tied for third at 13-under.
Kenny Perry closed brilliantly with a 64 to get to 12-under and finish tied for sixth. He had been criticized for skipping the British Open to play here after winning three of his last five tournaments including last week's John Deere Classic.
Perry had chosen to play in Milwaukee because he felt he had the best chance of picking up points so he can make this year's Ryder Cup team, which is played in his native Kentucky. He said his finish vindicated that decision.
"I accomplished my goal," Perry said. "I wanted to top 10 it. I told my people, I told my friends. I said, 'If I can just go there and have a good top 10, I've accomplished my mission.'"
However, defending champion Joe Ogilive failed in his bid to become the first player to win back-to-back titles in the tournament, which began in 1968. The Bank Championship and the Players Championship, which began in 1974, have gone longer than any other tourneys without a repeat winner.
Johnson started the day at 10-under, a shot back of third-round leaders Gavin Coles and Nick Flanagan. Like fellow Australian Greg Norman at the British Open, they failed to follow up their third-round lead with a victory. Coles and Flanagan each shot even-par-70 to finish tied for 11th.
The Swedish golfer struggled early with bogeys on two of his first four holes but made the turn only one shot back of Troy Matteson, Duke and Campbell, who were all at 12-under.
His bad day turned around after a bad shot on the par-5 sixth hole. After hitting his tee shot in the rough, he miss-hit the ball and it hit a tree and stayed in the rough. His next shot, however, found the green and he made a 15-footer for birdie.
"Then all of a sudden (I) just went, 'OK, I can do this.' From there on I played unbelievable," he said.
He birdied the next hole, a par-3, and got two more to start the back nine and begin his run to victory.