It took Anthony Johnson less than three minutes to ruin the party.
Johnson unleashed a brutal beating on Gustafsson in front of the second-largest crowd in UFC history Saturday night, scoring a TKO victory at 2:15 of the opening round.
With the victory, Johnson earns the next shot at UFC light heavyweight champion Jon Jones and capped one of the most remarkable turnaround stories the sport has ever seen.
"Alex did everything I thought he was going to do," the fighter nicknamed "Rumble" said. "He's an amazing athlete."
Early in the bout, Gustafsson (16-3), attempting to gauge distance, caught Johnson (19-4) with an accidental eye poke.
When the fight restarted, the carnage began. Johnson crushed Gustafsson with a huge overhand right to the jaw. While Gustafsson got to his feet after the knockdown, Johnson soon had him back on the mat for good. Referee Marc Goddard gave the hometown fighter every opportunity to get out of trouble, but eventually he had to call off the fight.
For years, the 30-year-old Johnson was considered a fighter with all the tools, but also a head case. He left the UFC under a cloud in 2012 after missing weight several times at both welterweight and middleweight.
After leaving, he finally went up to light heavyweight, then blossomed. He went 6-0 outside the UFC, and is now 3-0 since his return to the Octagon. He has all knockouts or TKOs in that span.
"Rumble" stayed humble in his post-fight interview.
"I feel bad because he's crying," Johnson said of Gustafsson. "I'm an emotional guy, he's an emotional guy. Hope you guys enjoyed the show."
Gustafsson has now dropped two out of three and was finished for the first time in his UFC career.