CHICAGO (Reuters) - Sweden's Richard Johnson made a hole-in-one on the par-three 14th on his way to a seven-under-par 63 to give him a one-stroke lead after Thursday's first round of the U.S. PGA Tour's Milwaukee Championship.

Johnson holed a seven-iron from 185 yards for his ace, which helped him record a five-under 31 on the back nine at Brown Deer Park golf course.

South African brothers Deane and Brenden Pappas, were tied for second after both registered 64s.

"I've been struggling this year," said 31-year-old Johnson, who has missed eight of 11 cuts on the PGA Tour this year. "I didn't really get anything going early.

"If you can get a little confidence going, all of a sudden the hole looks bigger, you start hitting shots that you believe in. If you've got no confidence going, you're always kind of spotting around and hoping to get a good score in."

Americans Dean Wilson, Patrick Sheehan and Robert Garrigus were tied for fourth place on 65.

Champion Joe Ogilvie of the U.S. was another shot back in a large group at 66 along with Swede Jesper Parnevik.

Among the players bunched at 67 was American Kenny Perry, winner of three of his last five PGA events including last week's John Deere Classic.

Perry had decided to skip the British Open and play instead in Milwaukee, where he enjoys the course and felt more confident about winning points toward making the U.S. Ryder Cup team.

Johnson said cold, wet conditions at Royal Birkdale on Thursday made many players content to be playing in Milwaukee.

"I said yesterday everybody blamed Kenny Perry to be kind of not the smartest man in the world to not go over there playing there when he's playing so well," Johnson said.

"But when you saw what they had to play in this morning, you'd have thought Kenny Perry was the smartest guy in the world."

(Writing by Larry Fine in New York; Editing by Greg Stutchbury)