Stricker, who had never finished in the top 10 in his 11 previous trips to Muirfield Village, built a big lead with more flawless golf on the front nine, then relied on his silky putting stroke for two clutch pars to hang on for a one-shot victory.
He closed with 4-under-par 68, lagging from 20 feet for a two-putt bogey on the 18th hole. By then, the hard work was over. Stricker saved par from bunkers on the 16th and 17th holes, making putts of 15 feet and 7 feet to go to the last hole with a two-shot lead.
"It wasn't pretty," Stricker said to tournament host Jack Nicklaus walking off the 18th green.
Matt Kuchar and Brandt Jobe each closed with 65 to tie for second.
The 44-year-old Stricker moves to No. 4 in the world and becomes the highest-ranked American for the first time in his career. He won for the 10th time in his career, and the seventh time since he turned his game around five years ago.
Dustin Johnson closed with 65 to finish fourth, followed by Rory McIlroy of Northern Ireland, who had 68. The biggest consolation prize went to Gary Woodland, who had 68 to finish alone in sixth. Woodland likely will move to about No. 40 in the world ranking, making him virtually a lock to get into the U.S. Open. He had faced a 36-hole qualifier this morning.
Stricker finished at 16-under 272 and earned $1,116,000. Almost as sweet as the trophy was getting a handshake and hug from Nicklaus behind the 18th green.
"It's pretty special walking off," Stricker said. "He's a friend, and it's truly an honor."
Luke Donald, in his first tournament at No. 1 in the world, never had a chance to win but never quit trying. Donald closed with 68 and tied for seventh, his 10th consecutive finish in the top 10 in worldwide golf.
Jobe has been battling injuries over the past several years, and the $545,600 pushes him over $1.16 million for the season and assures him keeping his card for next year. Jobe put the most pressure on Stricker by running off five consecutive birdies around the turn.
"I thought if we would have gone out and shot 65, that might have been good enough," Jobe said. "But it looks like we're going to be a little short. It was his tournament to kind of win or lose, and he's going out there and winning it."