Thorpe, who holed a bunker shot for eagle on the final hole Saturday, birdied the par-5 18th to force sudden death, and repeated the performance on the first extra hole to end the tournament.
'That hole was very kind to me,' Thorpe said. 'They should put my name someplace out there.'
Thorpe shot 2-under 70 on the Prospector Course in Superstition Mountain, Ariz., to collect his fifth career Senior victory to go along with $300,000. Jacobs shot 71.
'I'm not going to lie to you. I love craps. Tonight I'll be playing craps in Vegas,' Thorpe said. 'Next week in Alabama I'll be at the dog track. But I do the right thing, too. I give 10 percent to the church.'
More from Jim on his win
Charlie Sifford, in 1975 at the Senior PGA Championship, was the first African-American to win a Senior major, though he did so before the tour was officially formed in 1980.
The two players ended regulation tied at 11-under-par 277. Jacobs led by one entering the par-5 18th, but an errant tee shot led to an awkward stance for his second shot. Standing in the left fairway bunker, with his ball waist-high on the right cusp, Jacobs side-slapped his ball into the adjacent rough. He eventually made a clutch 12-footer for par, while Thorpe, following a stellar approach, made a nervous two-footer for birdie.
They went back to the 18th. Thorpe found the right rough off the tee, while Jacobs once again snap-hooked his driver, this time avoiding the bunker. Thorpe laid up perfectly in the fairway on his second shot; Jacobs pushed a metal-wood into the right gallery.
As he did 25 minutes prior, Thorpe struck a beautiful third shot to inside five feet; Jacobs, scrambling again, pitched from the trampled-down rough to nearly half that distance. Thorpe made his birdie, Jacobs lipped out his.
'I misread it,' Jacobs said. 'I certainly didn't miss it because I was nervous. If I'd been nervous, I would have missed the first one.'
Said Thorpe: 'It was a wonderful finish. If this doesn't help the golf ratings, I don't know what will.'
Jacobs started the day leading Thorpe by a shot. Thorpe tied for the top spot with a birdie at the sixth, but fell back to 9-under when he couldnt get up and down from the greenside bunker at the par-3 eighth.
Jacobs returned the favor by bogeying the par-4 ninth after missing the green.
The back nine proved early to be a series of missed opportunities on the part of Thorpe, and crucial saves for Jacobs.
The big-bombing Jacobs ' hes won more than 100 Long Drive Championships worldwide ' showed a deft touch in saving par from four feet at the 10th, from six feet at the 11th and from 10 feet at the 12th.
Meanwhile, Thorpe missed a six-footer for birdie at No. 10, an eight-footer at No. 11 and a 12-footer at the par-5 13th.
As the two remained stagnate at 9-under, the rest of the field moved into attack mode. Bob Gilder birdied the 14th to go to 9-under, as did Bruce Summerhays at the 15th. But, finally, Thorpe coxed in a 20-foot birdie from the fringe at No. 14 to take the outright lead at 10-under.
For the first time in the final round, Jacobs found himself looking up on the leaderboard. It didnt last long enough for him to get a crick in his neck, however. Jacobs hit a short pitch approach shot to four feet at the par-4 15th and converted the birdie to tie Thorpe at 10-under. He then moved one clear after running his approach shot from the left rough to within five feet of the hole at the par-4 16th.
After a routine two-putt par at the 17th, Jacobs carried a one-shot lead over Thorpe, Gilder and Summerhays into the par-5 18th. Both Gilder and Summerhays birdied 17.
Playing in the penultimate group, Summerhays had a six-foot birdie putt to tie Jacobs at 11-under, but missed on the low side to set the clubhouse target at minus-10. Gilder, playing alongside Jacobs and Thorpe, also went on to two-putt and finish at 10-under.
Jacobs found trouble off the tee at 18, toe-hooking his drive into the rough buffering the fairway and the left-hand bunker. With his ball resting outside the bunker he contemplated hitting his second shot left-handed, but instead dug down into the sand ' with the ball waist-high ' choked down on his iron and punched his ball into the deep right rough. He laid up in the fairway with his third shot.
Thorpes tee shot, meantime, landed in the left-hand bunker, from where he laid up into the middle of the fairway. He then stuck his third shot within two feet of the cup.
Jacobs approach into the green finished 12 feet right of the hole ' leaving him that for par and a probable playoff. And as he had done for most of the day, he converted the save.
Full-field scores from The Countrywide Tradition