In , Choi broke out offensively and became a star, rebounding from the slump. He helped the Tigers into title contention immediately, batting .308, blasting a pro career-best 33 home runs, leading the KBO league in runs with 98 and helping them win the 2009 KBO regular season. Choi was runner-up in home runs (33), RBI (100), and walks (103), 4th in slugging percentage (.589), 6th in on-base percentage (.435), and 11th in batting average (.308). Choi and Kim Sang-hyeon hit 69 home runs, and the two together are called the "CK Cannon".