The win was Choi's third on the PGA Tour. He captured the Compaq Classic of New Orleans and the Tampa Bay Classic in the 2002 season and now believes more victories are in his future.
Shigeki Maruyama holed out from a greenside bunker at the 18th en route to a 5-under 67. He finished alone in second place at 20-under-par 268 at Forest Oaks Country Club.
Charles Warren (65), Brandt Jobe (67) and 2005 B.C. Open champion Jason Bohn (70) shared third place at minus-17.
Choi got the flat stick going early as he drained a 17-foot birdie putt at the first hole. He two-putted for another birdie from 40 feet at the par-5 second, then rolled in a pair of 8-footers for birdie to pull ahead of the field.
His round certainly had some hiccups. He three-putted for a bogey at the fifth, but got the stroke back on the next hole when he sank a 12-footer for birdie.
Choi collected one more birdie on the front nine as he converted a 10-footer at the par-5 ninth. He missed a 4-foot par save at the 10th and his lead dipped to two, but an errant 5-iron sealed his victory.
At the par-3 12th, Choi hit a 5-iron into a greenside bunker. He blasted out 12 feet short of the stick, but the ball rolled into the cup for the unlikely birdie.
Choi ran home a 4-foot birdie putt at the 13th and that provided a three-shot cushion. He played conservatively from there, but did get a brief scare from Maruyama.
Maruyama came up short of the green with his approach at the 18th. He landed in a greenside bunker, but holed out from the trap, inching within two strokes of Choi's lead.
Choi had some testy putts coming into the winner's circle. He left himself close to 4 feet at the 17th, but converted. Choi had almost the same distance on 18, but calmly stroked it in and was off to hoist the trophy.
It might not come as a surprise that Choi played well this week. Last week, he missed out on The Presidents Cup as he finished 13th in automatic qualifying and International captain Gary Player elected not to add him to the team.
Choi also got a putting tip earlier in the week, so a lot added up to the victory.
'Literally 10 minutes before I went out for my first round, this feel came back to me like in 2002 when I had two victories,' said Choi, who missed Jesper Parnevik's 1999 tournament record by a single stroke. 'That same feeling came back to me. I was able to carry that throughout the tournament.'
Maruyama came up just short and knows that had he been able to get it going early in his round and match Choi, he could have picked up the win.
'I could hear K.J. making birdies at the beginning, and I couldn't make the putts the first few holes,' said Maruyama. 'I had good birdies on the fourth and fifth. I played very good golf on the last day, but K.J. just played very well.'
J.L. Lewis (66), Tim Clark (68), Jerry Kelly (68), Justin Rose (71) and Tim Herron tied for sixth at minus-15.