Choi Yong-soo quit as head coach of Jiangsu Suning on Thursday afternoon after a disappointing start to the season continued with his side's exit from the Asian Champions League against fellow Chinese Super League side Shanghai SIPG.
Jiangsu lost 3-1 on Wednesday evening to exit 5-3 on aggregate and, with the club struggling in the domestic league, Choi tendered his resignation.
"Due to personal reasons, Mr Choi Yong-soo has officially submitted his request to terminate his contact," a statement on Jiangsu's official social media account on Thursday evening said.
"After careful consideration, the club agreed to his request. Mr Choi Yong-soo will no longer serve Jiangsu Suning Yigou Football Club as the head coach with immediate effect.
"The club appreciates Mr Choi and his coaching team's hard work and their contribution to the club during the past year. We wish him and his team a bright future in their lives and their careers.
"From now on our Chinese coaching team will take over the training and coaching responsibilities temporarily. In the meantime, the club is seeking a new head coach who can lead Jiangsu in the right direction."
Choi, who represented South Korea as a player at the 1998 World Cup finals in France, guided Jiangsu to the runners-up position in the Chinese Super League and the Chinese FA Cup last season, finishing behind Guangzhou Evergrande on both occasions.
But the club's fortunes have been less impressive so far this season, with Jiangsu winning just once to date in the league to sit one point above the relegation zone before crashing out of the Asian Champions League at the round-of-16 stage.
Choi was hired after a successful five-year stint with FC Seoul in his native Korea, where he won the domestic league title in 2012 before steering the club to the final of the Asian Champions League a year later, where his side were defeated over two legs by Guangzhou.
That loss was not enough to deny him the Asian Football Confederation's Coach of the Year award and he went on to win the Korean FA Cup before moving to Jiangsu last summer, signing a two-and-a-half-year contract with the club.