Arlovski (23-10) received heavy criticism for a lacklustre win over Brendan Schaub in June. On Saturday night, he silenced his doubters, at least for now.
Silva (18-6) looked a little tentative to start, as he took the centre of the octagon but was reluctant to move forward, instead preferring to keep his hands high and seek a counter. Arlovski approached with caution to open, but once he realized Silva was holding back, he opened up with darting right hands to the head and body. It would be the punch that would ultimately prove the decider.
Late in the first, Arlovski fired the big overhand, and it landed flush, sending the massive Silva to the floor. Arlovski immediately seized the opportunity, pouncing with big hammerfists that put Silva out at the 2:59 mark of the opening round.
Silva — who goes by the nickname Bigfoot — defeated Arlovski in 2010 when both fought for the Strikeforce promotion.
"I am very excited and happy now," Arlovski said after the win. "And I really want the extra $50,000 on my paycheck."
Arlovski is now 2-0 in the UFC since rejoining the promotion after six years fighting outside of the octagon, and he did pick up a $50,000 bonus for one the card's two "Performance of the Night" awards, as well.
In the night's co-main event, massive Brazilian lightweight Gleison Tibau earned a hard-fought split-decision win over Polish prospect Piotr Hallmann.
Tibau looked destined to finish the fight in the early going, rocking Hallmann with a high kick and several powerful punches. But the gritty Hallmann refused to be put away, battling back throughout the 15-minute affair with punches and kicks of his own.
Tibau seemed to control the action throughout all three rounds, taking the fight to the floor when he wanted and remaining upright when Hallmann tried to do the same. Tibau's blows always seemed to land with more consequence, as well, though a few Hallmann knees did draw blood late in the third.
The bout was back-and-forth, but Tibau stayed just a step ahead, and while it looked like he had done enough to comfortable score a decision win, he had to sweat through a split result before picking up the win.
"It wasn't the result I wanted," Tibau admitted after the fight. "I won the fight, but I wanted the knockout. But I'm happy because I think Hallmann made my win better because he was really tough."
Tibau's 23 UFC appearances are now tied for fourth-most all-time.
In a lightweight matchup, "The Ultimate Fighter: Brazil 2" winner Leonardo Santos (13-3) picked up a hard-fought decision win over "The Ultimate Fighter 8" winner Efrain Escudero (22-9).
Santos, a jiu-jitsu world champion, controlled the opening round, taking Escudero to the floor and looking for submission opportunities. The tables turned in the second, with Santos seeming to fade as Escudero defending his takedown attempts and landing uppercuts and overhands on the feet. With the fight on the line in the third round, Escudero looked crisp to start, but it was Santos ultimately imposed his will.
Santos scored a well-timed takedown and then dominated the positioning for most of the final frame. While Escudero defended his submission well, he was unable to get back to his feet, and Santos was granted the unanimous decision win.
"He won the second round, and I know it, but I dominated the first and third rounds," Santos said after the win. "He is a very tough and experienced guy, so I had to look for flaws in his game. But I found it and won the fight."