Sinatraa

After achieving rankings of second in North America and fifth in the world on Overwatch's competitive mode, Won received an opportunity to try out for Selfless Gaming, an esports team based in Georgia, United States. Although he initially did not secure a spot on the team, he was given another chance a few weeks later. Following a review of his performance by head coach and co-owner Brad Rajani, he was ultimately signed to the team.[1] However, Selfless Gaming disbanded on July 7, 2017, leading to the conclusion of Won's association with the team.[2]

With the inception of the Overwatch League approaching in 2018, scouts from the twelve franchises sought to sign players to complete their teams. Won attracted significant attention and sparked a bidding war between NRG Esports and Cloud9. Initially inclined to join the London Spitfire, Cloud9's Overwatch team, Won eventually reconsidered his decision after further discussions with NRG and his parents. He opted to sign a contract worth US$150,000 per year with NRG's San Francisco Shock, three times the league's minimum salary, forging a reunion with head coach Rajani, who became the head coach of the Shock. Due to being 17 years old at the time, Won was ineligible to participate in league matches until he reached the age of 18.[3] He made his Overwatch League debut on March 21, 2018, against the Florida Mayhem. Despite a loss in that match with a score of 2–3,[4] Won quickly demonstrated his skills and solidified his status as one of the league's premier damage players. As he and his teammate Matthew "super" DeLisi became eligible to compete around the same time, the team achieved an 11–9 record in the latter half of the season 3.[5]

In the 2019 season of the Overwatch League, teams primarily utilized compositions consisting of three tanks and three supports during the first three quarters of the season. During this time, Won, who typically played as the damage hero Tracer, made a transition to playing as the tank hero Zarya. The San Francisco Shock, with Won's contributions, achieved impressive results, posting a perfect +28 map differential in Stage 2, reaching all three stage finals, and securing one stage title.[6][7] In July 2019, just before the final stage of the season, the league introduced a role lock system, requiring teams to adhere to a composition of two tanks, two supports, and two damage players. Following this change, Won primarily played as the damage hero Doomfist.[8] He concluded the season as the leader in hero damage dealt per 10 minutes and played a crucial role in helping the team achieve a regular season record of 23–5. Won received recognition as a Role Star for DPS and received the Overwatch League Most Valuable Player award.[7][9] After a loss to the Atlanta Reign in the first round of the 2019 season playoffs, the San Francisco Shock made their way through the lower bracket to secure a spot in the 2019 Grand Finals.[10] In the Grand Finals against the Vancouver Titans on September 29, 2019, Won played in two out of the four maps as the Shock clinched a 4–0 victory and emerged as the champions.[11] Following this Grand Finals win, Won and his San Francisco Shock teammate, Matthew "super" Delisi, appeared on The Tonight Show Starring Jimmy Fallon on October 7, 2019 to talk about their victory.[12]

Won announced his retirement from professional Overwatch on April 28, 2020, citing a "lost passion for the game".[13] In recognition of his MVP award, the Overwatch League released a commemorative in-game skin for the hero Zarya on June 16, 2020.[14] However, in March 2021, following sexual assault allegations that emerged, the Overwatch League offered refunds for the skin and removed the OWL Championship and MVP badges from the skin.[15]

Won was selected as a member of Team USA in the 2017 Overwatch World Cup (OWWC). Although the team faced defeat against Team South Korea in the quarterfinals, Won's performance throughout the World Cup caught the attention of NRG Esports CEO Andy Miller, ultimately leading to his signing there.[3][16] Won was once again selected to represent Team USA in the 2018 Overwatch World Cup.[17] Despite securing the top seed after the group stage, the team experienced a loss in the quarterfinals against Team United Kingdom.[18]

In the 2019 Overwatch World Cup, Won once again selected to represent Team USA, marking his third consecutive year participating in the tournament. Joining forces with his San Francisco Shock teammates Matthew "super" Delisi and Grant "moth" Espe, Team USA showcased their prowess as they navigated through the competition, emerging victorious in every match they played. The team's performance culminated in a sweeping victory against Team China in the OWWC finals on November 2, 2019, securing USA's first OWWC title. Won's contributions earned him the title of OWWC Most Valuable Player. Alongside super and moth, he became one of the four few individuals to have won both Overwatch League and Overwatch World Cup titles.[19]