Choi got up-and-down from the bunker on the par-5 18th to cap off a 4-under 66 and double the size of his margin, taking a four-shot lead into the final round as he tries to become the first outright wire-to-wire winner at Waialae in eight years.
The only threat on a balmy day by the Pacific came from a rookie who wasn't even on course.
Tim Wilkinson, a left-hander from New Zealand playing in only his third PGA TOUR event, birdied seven of his first 11 holes and finished with an 8-under 62 for the best round of the week. That left him four shots behind Choi, who shows no sign of cracking.
Choi was at 15-under 195.
Kevin Na, who started the third round two shots behind, couldn't keep up with Choi's birdie-birdie start and only a pair of birdies on the final four holes left him in the mix. Na shot 69 and was at 10-under 210 with Stephen Marino (68).
Another shot back was a group that included Chad Campbell, who sized up the situation for everyone chasing Choi.
'He's going to be tough,' Campbell said. 'He hits a lot of fairways, and that's what you have to do out here.'
Wilkinson at least has experience with a decent crowd at Waialae. He played the first two rounds with 17-year-old island favorite Tadd Fujikawa, who missed the cut. Fujikawa had the largest gallery the first two days, and while the fans ignored the newcomer from New Zealand, Wilkinson said it sure beat his last few years on the Nationwide Tour.
'It's a lot of fun playing in front of people. You hit a good shot, you actually get applause,' Wilkinson said. 'On the Nationwide Tour, you might hit a good shot and you get nothing.'
Even so, the gallery Sunday figures to be one-sided.
Choi is popular in these parts, with several fans showing up Saturday with South Korean flags. He birdied his first two holes from inside 10 feet and nearly made an ace on the fourth as he quickly expanded his lead.
Everyone else was playing for position.
'I figured I'd lose some ground to K.J.,' Marino said. 'I think I can (catch him), but I'll need some help from him.'
Campbell is hitting the ball well enough to catch Choi, although he needs some help. He was making a late charge up the leaderboard Friday until bogeys on three of the last five holes sent him back in the pack. Campbell was practically perfect everywhere except on the greens Saturday, hitting all 14 fairways and 18 greens. But he converted only four of them for birdie and finished with a 66.
That left him six shots behind at 9-under 201, along with Troy Matteson (65), Jay Williamson (66) and Rory Sabbatini (66).
'Happy with the round, happy with the way I'm hitting it,' Campbell said. 'Hopefully, I can get the putts to start falling.'
It looked early on that Choi wouldn't leave anyone with a chance.
He hit his approach to 3 feet on the opening hole for birdie, made a 10-foot birdie on the next hole, and his tee shot on the par-3 fourth took a few hops and hit the back of the cup before spinning 12 feet away. He had to settle for par.
The only player who seriously threatened Choi was already done for the day. Wilkinson made his final birdie as Choi was heading to the first tee, and the 11-under 199 stayed on the leaderboard the entire day.
Wilkinson quietly put together the best round of the tournament, starting with back-to-back birdies, and it included a bunker shot he holed on the seventh. He didn't get anyone's attention until two more birdies to start the back nine, putting him at 7 under for his round and threatening the course record.
But the birdies dried up until the end, when he hit a good wedge into 3 feet.
'It didn't come into my mind at all, funnily enough,' Wilkinson said about a course record (60) or better. 'But on 12, 13, 14, I left them right in the middle. So had those gone in, I probably would have thought about it.'
The 29-year-old Kiwi seems unflappable, and he has a history of that. He started the final round of Q-school on the cut line, then closed with a 68 to tie for 14th and earn his card for the first time.
'The night before the final round at Q-school, I slept nine hours straight,' he said. 'I wasn't even worried about it. I was right on the number. And that night, I couldn't sleep that night after I qualified. It meant a lot.'
He'll get plenty of time to sleep in Sunday, and maybe nerves will set in eventually.