Andrei "The Pitbull" Arlovski surprised fans at UFC Fight Night 51 this past weekend by knocking out Antonio "Bigfoot" Silva during the main event at 2:59 in the first round.

The victory marks the former UFC champion's second fight in the promotion since leaving six years ago, and allowed him to avenge his loss to Silva in 2010, according to MMAjunkie.

"I train hard, I worked a lot," Arlovski said after the fight. "It was very important to me; I definitely wanted to knock him out. Nothing personal."

The fight also marks Silva's return after being suspended for nine months for failing a drug test after his fight with Mark Hunt in December 2013, Sporting News reported.

Silva won his previous fight with Arlovski via decision while the two fighters were in Strikeforce. Unlike his last fight at UFC 174 in June, Arlovski appeared much calmer in his rematch with Silva. He was able to land several punches before knocking Silva down with a right hook and landing several hammerfists while Silva was on the ground, resulting in the referee jumping in to stop the fight.

The Pitbull's cornerman had to talk him off the octagon after Arlovski responded to boos from the audience by cursing at them, MMAjunkie reported.

However, he would later thank the crowd, adding, "You guys boo me, but it motivates me even harder."

The upset victory puts Arlovski at 2-0 in his UFC return, Sporting News reported. Arlovski now has a range of potential opponents in front of him, such as Ben Rothwell, Stipe Miocic, Mark Hunt and Royal Nelson. Hunt and Nelson will square off in the main event of UFC Fight Night 52 next week.