'I felt good going into today,' said Els, who posted a final-round 65. 'All week, I was quite patient. So I felt it was there.'
Els, who defeated Aaron Baddeley in a playoff to capture this event last season, finished regulation tied with Frazar at 18-under-par 262 after both players birdied the 72nd hole to deny each other the victory.
The duo returned to the par-five 18th to begin the sudden death playoff and Els dropped his tee shot in the fairway. Frazar left his drive in a fairway bunker giving Els the early advantage, but he seemingly gave it away.
Els sent his second shot into the grandstand behind the green while Frazar played his second from the sand 40 yards short of the putting surface. Frazar then dropped his third inside 16 feet before Els took relief in thick rough.
Els lifted his third shot over a greenside bunker short of the green before playing his fourth within six inches of the hole. Frazar then two-putted for par followed by Els' tap-in to extend the extra session.
The pair went over to the 10th tee and Frazar found trouble again with an errant tee shot. After a solid drive, Els knocked his approach to eight feet but, Frazar managed to scramble to the green and leave himself 10 feet for par.
After Frazar converted, Els' birdie try for the win missed to the right of the cup. The Big Easy tapped in and the duo was off to the par-three 11th.
Both players reached the green off the tee, but left themselves with hefty birdie putts. Frazar missed his long birdie try before Els rolled in the decisive putt for his first victory of the new year.
'I almost had a similar line this afternoon,' Els said of his winning putt. 'So I knew where the line was going, it was all the difference.'
Els, who pocketed $864,000 for the win, was one shot back of Frazar to start the day at Waialae Country Club, but after Frazar struggled with back-to- back bogeys on the front side, Els took the lead for the first time with a birdie at the eighth.
Els two-putted for a birdie at the ninth, but Frazar battled back with four consecutive birdies from the ninth that were capped off by a chip-in birdie at the 12th.
The South African played his second shot from a bunker within a foot of the hole for a tap-in birdie at the 12th to reach 16-under and regained the outright lead with a chip-in birdie at the very next hole.
At the par-four 14th, Els almost holed out from the fairway as the gallery gasped while his approach rolled inches by the cup. Els then converted the comeback birdie to pull two shots clear of Frazar.
Els stumbled with a bogey at the 15th, however, and Frazar matched him at minus-17 with a birdie of his own at the par-three 17th.
Els then birdied the 18th, but Frazar, who reached the green in two at the par- five, two-putted for a birdie of his own to extend the tournament in an eventual losing effort.
'Obviously, I'm disappointed and this is going to hurt for a while, but I feel like I take with me the fact that I went toe-to-toe with Ernie,' said Frazar, who posted a 66 in the final round. 'So even though it hurts, there's a lot of positives to take from it.'
Davis Love III finished alone in third place at 15-under-par 265 after a round of 67. He was followed by Frank Lickliter at 14-under-par 266.
Briny Baird and Jerry Kelly shared fifth place at 13-under-par 267 while John Riegger finished alone in seventh at 12-under-par 268.
Stephen Ames joined Craig Barlow in a tie for eighth at 11-under-par 269.
Vijay Singh was one shot further back at 10-under-par 270 along with Omar Uresti, John Huston, Paul Azinger and Retief Goosen.