Kizzire, who won the OHL Classic in Mexico last fall, closed with a 2-under 68.
That turned out to be the easy part.
Hahn shot 62 in the final round Sunday and got into a playoff with Kizzire at 17-under 263.
They matched two pars and two birdies on the par-5 18th. They matched pars when they went to the par-3 17th. It ended on the par 3 along the Pacific Ocean when Hahn putted from right of the green to about 8 feet, and his par putt caught the lip.
"It wasn't pretty," Kizzire said. "I'll take it any way I can get it."
Hahn, who won both his PGA Tour events in playoffs at Riviera and Quail Hollow, had birdie putts from 10 feet and 6 feet on the par-5 18th hole at Waialae Country Club that would have won it. He made a 6-foot birdie another time to extend the playoff.
Kizzire had to get up-and-down from a bunker for par on the first extra hole, making a 7-footer to stay alive.
This was the longest playoff on the PGA Tour since Bryce Molder won the Frys.com Open in 2012 in eight extra holes.
It nearly was the most exciting tournament of the year (it's only the second week) that no one saw. Union workers for video and audio production at Golf Channel events walked out Sunday over a labor dispute, and the network had to scramble to provide limited coverage. It had enough cameras to at least cover the final three holes and the entire playoff, with commentary coming from headquarters in Florida.
Missing from the playoff was Tom Hoge, who did everything right in his bid to win for the first time on the PGA Tour except for one swing. He had a one-shot lead when he was between clubs on the 16th hole, and opted to hit a draw to the back-left pin. He turned it too much and it found the bunker. His next shot got hung up in the shaggy rough, he chipped that to 12 feet and missed to make double bogey to slip one shot behind.
Hoge gave himself two good chances with putts of about 7 feet. Both burned the edge. He shot 70 and had to settle for third place, his best finish on the PGA Tour.
"This sets me up a lot better for the rest of the year, and hopefully made the FedEx Cup playoffs," said Hoge, a 28-year-old from North Dakota who hasn't kept his full card his previous three years on tour. "More so just the confidence I had to play in the final group and play well today."
Brian Harman, who played in the final group at both Hawaii events, was two shots behind after a tap-in birdie at No. 12. But he three-putted for bogey from long range on the 13th, took two shots to get out of the bunker left of the 16th green and had to settle for a 70. He tied for fourth.
Defending champion Justin Thomas closed with a 68 and tied for 14th. Jordan Spieth finished with eight straight pars for a 66 and tied for 18th, ending his streak of seven consecutive top-10s dating to the PGA Championship in August.
Kizzire, starting the final round one shot behind Hoge, made all pars on the front nine until his fortunes turned on the short par-4 10th. From the rough behind a bunker just to the right of the 10th green, his chip was running hot and looked as though it might not stay on the green until the hole got in the way and it dropped for eagle. Then, he holed a 15-foot birdie putt on the par-3 11th for his first lead of the round.
Hahn finished nearly an hour ahead of the last group. He ran off seven birdies in an eight-hole stretch starting at No. 8 to reach 17 under, only to make three pars coming in, including the par-5 18th.
Kizzire saved par from behind the 17th in regulation and could have won with a birdie on the final hole. But from short of the green in two, his chip ran about 15 feet by the hole and he missed it on the low side to take par.
Six more holes later, he had no complaints.