The club's debut match was a Second Round tie in the 2010 Korean FA Cup however they suffered a home defeat to Kwangwoon University, losing out 7–6 on penalties after the tie had finished 1–1 after extra time. Yongin City made a solid start to life in the National League in 2010, then the unofficial second tier of football in Korea, finishing with the sixth-best overall record of all clubs in the division for 2010. Jung Ji-soo and Oh Chul-suk finished joint-top scorers for the club with six goals each during the campaign.
Professional encounter
Yongin endured a difficult second season during 2011 as they finished eleventh out of the fourteen teams that took part in the competition that year. That season's FA Cup competition saw them come up against professional K-League opposition for the first time when they were drawn to face FC Seoul at the Seoul World Cup Stadium. Yongin lost the match 4–0.
2012 National League playoff run
2012 proved to be Yongin's best ever league campaign to date as they finished the 26-game league campaign in sixth place and qualified for the post-season championship playoffs. In their first match they were drawn to play third-placed Gangneung City and Yongin triumphed 4–2 on penalties after the game finished goalless. That victory set up an encounter with Incheon Korail however Yongin were defeated 3–1 by the team that would go on to win in the championship playoff final. Despite a solid league campaign Yongin exited the 2012 FA Cup at the first hurdle yet again as their Second Round encounter with National Police FC ended in a 4–0 home reverse. There was to be some success for the squad at the National Sports Festival football tournament in October that year as they finished joint-third with Gimhae FC and were awarded the bronze medal having been eliminated at the semi-final stage 10–9 on penalties by Gangneung City.
First FA Cup tie win
The club failed to build on the relative success of 2012 as they finished second-bottom of the much reduced-in-size 2013 National League season, the league having effectively been reduced in status to the unofficial third tier of football in Korea following the creation of the K League Challenge. Although Yongin finished ninth out of the ten sides they were just five points adrift of fourth place and the final championship playoff spot. The club recorded their first ever win in FA Cup competition during the 2013 edition of the tournament with a 1–0 win over Kyunghee University in the Second Round. That victory set up a Third Round clash with K League Classic side Jeonbuk Hyundai Motors however Jeonbuk won 2–0.
