The 24-year-old Lee took full advantage of his straight driving game to hit nine birdies against a bogey and double bogey at the impressive Haesley Nine Bridges Golf Club while Choi opened with a 67 for tied second place in the US$750,000 event sanctioned by the Asian Tour and Korean Golf Tour.
Another young Korean Kim Do-hoon, a former Asian Games team gold medal winner, also returned a 67 while American star Anthony Kim stormed home in 31 for a 68 to lie two strokes off the pace with Australians Scott Hend and Adam Groom.
Lee, who is searching for a first professional victory, did not miss a single fairway as he attacked the pins relentlessly. Despite blemishes on two holes, a birdie conversion from 24 feet on 17 gave him the overnight one-shot lead.
"That was my best putt [on 17]. Before the round, I knew the course was difficult but I had a good feeling with my game today [Thursday]," said Lee, whose card included four straight birdies on the front nine.
"It's good I'm in a high position and also above K.J. I have a lot of respect for him as he helped me once when I was a junior. He came to my hometown seven years ago and gave a clinic and I was amongst those who had the opportunity to learn from him. I will always remember that experience."
The 41-year-old Choi, an Asian Tour honorary member and eight-time winner on the PGA Tour, fired an early warning that he was ready to win his own event after sinking seven birdies against two bogeys. It was an eventful day for Choi, the world's number 14, as his round included a forgettable four-putt bogey at the seventh par five hole.
"I'm very happy. I started a bit slow as I woke up at 5 am and it was very cold outside. The body was a bit slow but the sun came out very quick which made it warm," said Choi. "I made mistakes on seven and nine but five under is a good position. I'm in a rhythm right now and I think my four rounds will be pretty steady."
Anthony Kim, who has three wins in the US, turned on the style with his putter as he came home with five birdies after turning in 37. "I haven't hit the ball that well in a long time," enthused the former Ryder Cup star who was out of action earlier in the season due to a thumb surgery.
"I just holed a couple more putts on the back nine. I hit it pretty good on the front but didn't make any putts. It was a good day, a positive day as far as moving in the right direction with my golf game. The swing felt good. I'm excited about what's to come. It gives me a good frame of mind. Hopefully I can make a few more putts."
A blurry-eyed Hend battled to five birdies against a dropped shot as he launched his bid for a second Asian Tour victory. Like Choi, he also suffered a four-putt bogey at the lightning-quick 12th green. "A bit of a concentration lapse there but that's alright as I only slept for an hour last night [Wednesday] due to jetlag. It's a good start," said Hend.
With playing rights in Asia and Europe, the Florida-based Australian has travelled extensively around the world which has taken its toll. "I'm in a different place every week. I was in Japan, Scotland, Florida, India, now here and then I go back to Florida and after five days at home, I'm back to Taiwan. It's just a constant time change but you do sleep when you're tired!" said Hend, who is ranked 42nd on the Asian Tour's Order of Merit.
"My season has been very disappointing so far. I've been working hard without getting the results. Hopefully it's showing some promising signs for the end of the year. It'll be nice to have some solid finishes. I know I can play well but it's just a matter of pulling that out from inside of me."
Scores after round 1 of the CJ Invitational Hosted by KJ Choi being played at the par 72, 7,229 Yards Haesley Nine Bridges GC course (a- denotes amateur):
66 - LEE Min-chang (KOR).
67 - KIM Do-hoon-753 (KOR), K.J. CHOI (KOR).
68 - Scott HEND (AUS), HWANG Jae-min-471 (KOR), Anthony KIM (USA), Adam GROOM (AUS), David OH (KOR).
69 - JUNG Jae-hoon (KOR), MAENG Dong-seop (KOR), Young NAM (KOR), LEE Tae-hee (KOR), Prom MEESAWAT (THA).
70 - LEE Dong-hwan (KOR), KIM Wi-joong (KOR), KIM Chang-yoon (KOR), Tony CAROLAN (AUS), LEE Kyoung-hoon (KOR), CHOI Joon-woo (KOR), LEE Ki-sang (KOR), MO Joong-kyung (KOR), Zaw MOE (MYN).
71 - SONG Ki-joon (KOR), KANG Kyung-nam (KOR), HWANG Inn-choon (KOR), Anirban LAHIRI (IND), PARK Hyun-bin (KOR), KIM Gi-hwan (KOR), YANG Ji-ho (KOR), Thanyakon KHRONGPHA (THA), HAN Min-kyu (KOR), BAEK Seuk-hyun (KOR), Thammanoon SRIROJ (THA), Niall TURNER (IRL), KIM Seung-hyuk (KOR).