With nine holes to play, Stricker led by five strokes. With two holes left, he was two shots down.
Twice, Stricker buried shots deep in bunkers, one so far under the sand he had a hard time finding the ball. At a third bunker, he had to take an awkward stance just to give himself a chance to swing.
But he won nevertheless, sinking a 25-foot putt from off the 18th green Sunday to beat rookie Kyle Stanley by one stroke.
"It became hard, real hard," said Stricker, who was grateful for the encouraging words from caddie Jimmy Johnson.
"Jimmy was right there telling me the whole time, you know, it's not over yet, just keep plugging, you never know what's going to happen," Stricker said. "And sure enough, he was right. Just play it all the way out and see what happens."
Stricker's clutch putt capped a roller coaster round on a steamy afternoon and gave him a 2-under par 69, good enough to make him the 10th golfer since World War II to win a tournament three straight times.
Despite a double-bogey on No. 5, when he needed two shots to get out of a greenside bunker, and bogeys on 15 and 16, Stricker finished at 22-under 262. Stanley, 23, whose best finish previously had been a tie for 12th at the Arnold Palmer Invitational in late March, closed with a 66.
"It was an unbelievable week and an unbelievable finish," Stricker said. "I still can't believe I'm sitting here."
Matt McQuillan, who had missed the cut in his previous 10 tournaments, shot a 64 to tie Zach Johnson (65) for third at 17 under. Charles Howell III (64) and Chez Reavie (72) were another stroke back.
Stanley zoomed in front with birdies on five of the first six holes on the back nine, and kept the lead by salvaging par on 17 after sending his tee shot into a grove of trees. But he missed a 9-foot par putt on 18 to open the door for Stricker, who took advantage.
Stricker had fallen two behind with those back-to-back bogeys, which seemingly ended his hopes of a threepeat.
"I really did feel like the momentum was gone for a while," he said. "Those holes kind of derailed me there."
But he regrouped quickly. Stricker knocked in a 15-foot putt for birdie on 17 to cut Stanley's lead to one stroke, then made what turned out to be a tournament-saving shot from a bunker on the left side of the fairway on 18.
Standing with his left foot in the bunker and his right foot on the lip, Stricker hit the ball solidly and left it on the fringe of the green behind the pin, drawing a huge roar from the crowd.
The next roar was even louder. Using his putter, Stricker sent the ball toward the cup and watched it curl in from the left side. The 44-year-old from Madison, Wis., a crowd favorite at this tournament, backed away as the ball neared the hole, then raised his arms and pumped his fist to celebrate the moment.
"It's weird," Stricker said. "When I get into a situation where I have to make a putt, I feel like my nerves kind of go away and I focus extremely hard on trying to make that putt. And that's kind of like the little zone I got into on 17 and 18, I guess."
With the victory, Stricker joined a small but noteworthy group of golfers who have won a tournament three years running. The list reads like a Who's Who's of the game and includes Tiger Woods, Arnold Palmer, Jack Nicklaus, Tom Watson, Ben Hogan and Johnny Miller.
Woods has done it six times and Palmer twice.
"I kept telling myself that it's not a big deal and it really wasn't — until today," Stricker said. "That back nine trying to win, it's just really hard. I don't know any other way to say it. It's extremely hard to put it away.
"When you watch guys like Tiger put away all those tournaments, anybody who's put it away down the stretch, it's a difficult thing to do. But I'm happy to come out on top. I made a couple of putts when I had to."
Woods also is one of just four golfers who has won a tournament four straight years. The way Stricker has mastered the TPC Deere Run course, you can't discount his chances of joining that group, too.
Stricker finished 26 under at last year's tournament and was 20 under in his 2009 victory.
So, was he ready talk about four in a row.
"No," Stricker said with a smile.
Stanley claimed a nice consolation prize, earning the spot in the British Open that goes to the highest finisher in this tournament who's not already qualified. But if it hadn't been for Stricker's late heroics, Stanley would have had his first victory on the tour.
"I'm very excited to go over there," he said. "But I'm still trying to calm down from that round."
Stanley trailed by five strokes after Stricker buried a 50-foot birdie putt on No. 9. But showing the poise of a tour veteran, he went on his birdie run to take the lead, making a 26-foot birdie putt on 13, an 18-footer on 14 and a 36-footer on 15 to go up by a stroke.
"I just kept giving myself good looks and putts that I did in practice rounds and putts that I knew what they were going to do," he said. "I just kept trying to make birdies and give myself opportunities."
After his par save on 17, Stanley got into trouble on 18 when he went from the rough to a greenside bunker. He was in good position to salvage par again when he chipped up to 9 feet, but he missed the putt and took bogey, giving Stricker the opportunity he needed.
Stricker won for the second time this year and 11th time in his career, with eight of those victories coming after he turned 40. He won the Memorial a month ago and now has multiple wins in three consecutive years.
Only four others have done that since 2000: Woods, Phil Mickelson, Vijay Singh and Ernie Els.
Final scores and winnings
Steve Stricker (500), $810,000 66-64-63-69—262
Kyle Stanley (300), $486,000 65-67-65-66—263
Matt McQuillan (163), $261,000 64-69-70-64—267
Zach Johnson (163), $261,000 66-69-67-65—267
Charles Howell III (105), $171,000 66-68-70-64—268
Chez Reavie (105), $171,000 66-62-68-72—268
Cameron Percy (88), $145,125 66-67-67-69—269
Brendon de Jonge (88), $145,125 66-66-63-74—269
Briny Baird (75), $121,500 68-70-68-64—270
Brian Gay (75), $121,500 68-67-69-66—270
Cameron Tringale (75), $121,500 70-66-65-69—270
Sunghoon Kang (58), $85,500 72-65-68-66—271
Michael Putnam (58), $85,500 70-68-67-66—271
Kris Blanks (58), $85,500 63-71-70-67—271
Michael Thompson (58), $85,500 71-66-67-67—271
Davis Love III (58), $85,500 64-70-69-68—271
Aron Price (58), $85,500 69-66-67-69—271
Arjun Atwal (52), $60,750 67-66-70-69—272
Marco Dawson (52), $60,750 68-69-66-69—272
Charles Warren (52), $60,750 67-68-67-70—272
Dean Wilson (52), $60,750 69-65-67-71—272
Chris Kirk (46), $39,488 68-69-70-66—273
Kirk Triplett (46), $39,488 68-65-73-67—273
Andres Gonzales (46), $39,488 68-68-69-68—273
Brett Wetterich (46), $39,488 69-68-67-69—273
Michael Letzig (46), $39,488 70-65-68-70—273
Scott Stallings (46), $39,488 69-66-68-70—273
Todd Hamilton (46), $39,488 70-66-67-70—273
David Mathis (46), $39,488 68-65-69-71—273
Tim Petrovic (38), $26,156 69-69-69-67—274
Jason Bohn (38), $26,156 72-66-68-68—274
Troy Merritt (38), $26,156 68-68-69-69—274
Chris Couch (38), $26,156 70-65-69-70—274
Bryce Molder (38), $26,156 71-66-67-70—274
Woody Austin (38), $26,156 69-67-67-71—274
Will MacKenzie (38), $26,156 67-70-66-71—274
Mark Wilson (38), $26,156 65-67-68-74—274
Steven Bowditch (30), $18,450 67-68-72-68—275
Kent Jones (30), $18,450 70-68-69-68—275
Heath Slocum (30), $18,450 70-66-70-69—275
Ben Martin (30), $18,450 67-70-68-70—275
Jim Herman (30), $18,450 66-68-70-71—275
D.A. Points (30), $18,450 66-68-70-71—275
Shane Bertsch (30), $18,450 71-66-67-71—275
D.J. Trahan (21), $11,864 67-70-74-65—276
Alex Prugh (21), $11,864 69-68-72-67—276
Rod Pampling (21), $11,864 69-69-70-68—276
Frank Lickliter II (21), $11,864 68-70-69-69—276
Josh Teater (21), $11,864 66-70-70-70—276
Scott Piercy (21), $11,864 70-67-69-70—276
Craig Bowden (21), $11,864 67-70-69-70—276
John Mallinger (21), $11,864 68-65-70-73—276
Lee Janzen (21), $11,864 66-68-69-73—276
Cameron Beckman (21), $11,864 66-69-68-73—276
Brian Davis (21), $11,864 70-66-67-73—276
Chad Campbell (14), $10,170 67-69-70-71—277
Billy Mayfair (14), $10,170 67-66-72-72—277
J.J. Henry (14), $10,170 68-68-69-72—277
John Merrick (12), $9,990 67-71-67-73—278
Michael Connell (9), $9,720 69-66-73-71—279
James Driscoll (9), $9,720 71-67-70-71—279
Joe Ogilvie (9), $9,720 69-67-71-72—279
William McGirt (9), $9,720 67-67-71-74—279
Nathan Green (9), $9,720 69-64-69-77—279
Michael Sim (5), $9,360 67-70-70-74—281
John Rollins (5), $9,360 72-65-69-75—281
Steve Marino (5), $9,360 64-66-73-78—281
Jason Day (2), $9,090 67-69-75-71—282
Jhonattan Vegas (2), $9,090 68-64-75-75—282
David Hearn (2), $9,090 67-69-71-75—282
Chris Stroud (1), $8,865 69-64-76-74—283
Troy Matteson (1), $8,865 67-69-72-75—283
Duffy Waldorf (1), $8,730 67-69-73-76—285