As he has done to the likes of Cheick Kongo, Matt Mitrione and others, Nelson landed his heavy right hand and dropped Nogueira, flooring the former interim UFC heavyweight champion. Nelson, a former winner of The Ultimate Fighter, offered plenty of respect to Nogueira after the fight.
"He's a legend," said Nelson, who improved to 20-9 with the first round win. "Thank you. If it wasn't for him, there wouldn't be fighting in MMA. He's the heavyweight (legend)."
In the co-main event, Clay Guida picked up his second featherweight victory, besting Tatsuya Kawajiri via decision. Other main card results saw Ryan LaFlare defeat John Howard and Ramsey Nijm finish Beneil Dariush.
Nelson and Nijem each earned "Performance of the Night" bonuses and an extra $50,000, while Guida and Kawajiri were named the "Fight of the Night."
The attendance was announced at 7,963, which UFC president Dana White stated was a sellout, for a live gate of $1.8 million.
Complete results can be found below:
Roy Nelson def. Antonio Rodrigo Nogueira via KO (right-hand) at 3:37 of Round 1
Clay Guida def. Tatsuya Kawajiri via unanimous decision (30-27, 30-27, 30-27)
Ryan LaFlare def. John Howard via unanimous decision (29-28, 29-28, 29-28)
Ramsey Nijem def. Beneil Dariush via TKO (strikes) at 4:20 of Round 1
Jared Rosholt def. Daniel Omielanczuk via unanimous decision (30-27, 30-27, 30-27)
Thales Leites def. Trevor Smith via TKO (strikes) at :45 of Round 1
Jim Alers def. Alan Omer via split decision (29-28, 28-29, 29-28)
Johnny Bedford vs. Rani Yahya is declared a no-contest due to accidental head butt at :39 of Round 1
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