Huston broke into red figures at the par-5 second when he hit a 4-iron to 35 feet and two-putted. He parred the next four holes, then wedged his approach to 6 feet to set up birdie at the seventh. Huston made it back-to-back birdies when he rolled in a 15-footer at the eighth.
Huston made the turn and wasted little time in collecting birdies. He hit a 9-iron inside 3 feet for an easy one at the 10th, pushing him to 10 under par for the championship.
At the par-5 13th, Huston came up just short of the green with his second. He chipped inside a foot for the tap-in birdie, then took sole possession of the lead in a dramatic way at 16.
Huston missed the green short at the par-4 hole and chipped in from 30 feet out to get to minus-12.
'I've played pretty solid this week,' said Huston. 'I think definitely I've made a lot of putts, my short game's been pretty good, which has held the round together. Haven't been having to count too many bogeys. I think that's been the key.'
Huston has some work to do if he is to retain his PGA Tour card for the 2006 campaign. He is currently 127th on the money list and his exemption from winning the 2003 Southern Farm Bureau Classic runs out at the end of this year.
'I was in such a bad position, really bad, probably a couple months ago,' said Huston. 'I decided just to start playing every week, see if I could kind of get some sort of a feel for the game back, not think so much about mechanics. I've started playing a little bit better.'
In order to claw up the money list, Huston has teed it up in 14 of the last 15 tournaments. The only week off Huston had was the PGA Championship, and now Huston has one more year in his sights.
'I could either just kind of halfway give up for the year, or start playing every week and try to get myself back into a decent position,' said Huston. 'I really just decided I wasn't ready to give up on the game yet, so I just decided the best way to go about getting myself back into a better position would be to just start playing every week.'
Choi teed up on 10 Friday morning, but struggled on his front side. He made only one birdie, at the par-5 15th, but things turned around on his second nine.
He birdied the second, but dropped a shot at No. 5. Choi closed with birdies at seven and nine to get within one shot of Huston's lead, a shocking occurrence considering his start.
Choi had trouble with the cooler morning conditions and found himself hitting wayward shots to the right. He rectified the problem on the second nine and is in position for his third PGA Tour victory.
'His irons are playing great right now, so he's actually going to be attacking the third round with aggressiveness,' Choi said through an interpreter.
Tim Clark (69), Shigeki Maruyama (65), John Rollins (68) and Brian Gay (66) are knotted in fifth place at minus-9.
First-round leader Charles Warren struggled to a 2-over 74 and fell into a tie for ninth. Carl Pettersson (67), Daniel Chopra (69), Tim Herron (66) and Jason Bohn (65) joined Warren at minus-8.
The 36-hole cut fell at 3-under-par 141 and 2004 champion Brent Geiberger will not be successfully defending his title. He posted a 3-under 69 on Friday, and missed the mark by a shot.