What happened: Julian Erosa rallied through opening-minute trouble to stop JeongYeong Lee with punches at UFC Vegas 123. Immediately after having his hand raised, Erosa announced his retirement from active mixed martial arts competition.

Why it matters: The victory concludes Erosa's professional career on a high note after entering the contest as a underdog and facing for a knockout finish. The walk-away stoppage ensures he departs the roster on a victory rather than pursuing additional matchups.

What to watch: The UFC will adjust its featherweight matchmaking moving forward, while Lee looks to regroup following the first-round defeat.