Brazil's Pacheco scored a surprise victory over Harrison, the two-time US Olympic Judo champion, after a five-round battle to win the PFL lightweight title and the million-dollar prize at Madison Square Garden .
Pacheco, whom Harrison has beaten twice before, was knocked down in the first round but was successful in his high-profile fight in the second.
A triangle choke briefly confused Harrison in the third, while Pacheco attempted a back choke in thefourth to show his threat on the ground.
When Pacheco received a championship belt and over a million dollar check,he credited his opponent with playing a role in getting him to where he is now in his career.
"Like Kayla said before: I make her a better competitor," Pacheco said through an interpreter. "Well, it makes me a better competitor. It's driven me this time."