Watch: Rey Mysterio Wins United States Champion, Becomes Grand Slam Champion

Rey Mysterio won the United States Championship for the first time in his career on Sunday night, defeating Samoa Joe in approximately one minute at Money in the Bank.

The match ended in controversy when Mysterio countered a powerbomb attempt from Joe into a roll-up. Joe got one of his shoulders up, but the referee still made the three count.

Enraged by losing the title, Joe viciously attacked Mysterio as he and his son Dominick made their way up the ramp, Joe tossed Mysterio back into the ring and continued to beat him down, all while daring Dominick to try and stop him. The young man backed down, and Joe eventually walked towards the back.

The win gave Mysterio the honor of being the latest Grand Slam Champion, having won a world title, a tag title and both of the midcard championships at least once throughout his career. Mysterio is the 14th man to hit the career milestone under the modern rules, joining the likes of Kofi Kingston (who made the list just last month by winning the WWE Championship), Jeff Hardy, all three members of The Shield, Randy Orton, Chris Jericho, Daniel Bryan, The Miz, Big Show, Kurt Angle and two of Mysterio's former tag partners in Edge and Eddie Guerrero.