Henderson controlled the main event from the start, just a few miles from where he grew up in Federal Way. With the partisan crowd chanting Henderson's name throughout the fight, he took a decisive 50-43, 50-45 and 50-45 decision, his second successful title defense.
Prior to the main event, rising Canadian star Rory MacDonald took apart former champion B.J. Penn in a decisive unanimous decision that left Penn's face blooded and his body throbbing from body shots.
In the light heavyweight division, Sweden's Alexander Gustafsson won a unanimous decision over former champion Mauricio "Shogun" Rua, likely earning himself a shot at the light heavyweight title next year.
Henderson had a shaky first defense of his lightweight title when he took a decision in a rematch with Frankie Edgar in August. Henderson was showered with boos after the split decision in his favor was announced during UFC 150 in Denver, a fight the crowd believed Edgar had won.
There was no debate this time. Henderson left Diaz's face bruised and bloodied, while it was tough to tell if he'd even been in a fight. Henderson regularly got Diaz on the mat and retained control from the top, unloading punches and elbows at will. At one point, Henderson was on top just far enough away that Diaz's flailing punches couldn't land. Diaz got frustrated to the point of making an obscene gesture that forced Fox to cut away from its television coverage.
The only moment of concern for Henderson came in the third round when both grappled on the mat trying for ankle submission holds. Henderson eventually wiggled free and retained control.
Henderson improved to 6-0 with the UFC and 18-2 in his MMA career. Diaz fell to 16-8 after winning his last three fights.
The two fights before the main event saw youth get the better of experienced former champions.
Penn (16-9-2) could not break down the faster, younger, longer MacDonald (14-1) despite having huge fan support. Instead it was the Canadians who made the short drive across the border who were left cheering the unanimous decision in favor of the rising star.
MacDonald's jabs and combination punches, combined with snapping kicks left Penn's face bloodied and swollen and his ribs aching, especially in the second round. MacDonald caught Penn with a left-kick midway through the round that nearly doubled Penn over in pain. Penn was left protecting his ribs the rest of the fight, while MacDonald showed off for parts of the third round dancing and failing his arms, mocking the former champion.
MacDonald won 30-26, 30-26 and 30-27, then immediately asked for a rematch against Carlos Condit following the victory. Condit is the only fighter to beat MacDonald back in June 2010.
Penn, a former champion in both lightweight and welterweight classes, was fighting for the first time in 13 months. Despite some barbs tossed before the fight, MacDonald was respectful of Penn in victory.
"With all the things we said to each other hyping the fight I just want to say that it has been a huge honor fighting B.J.," MacDonald said. "I'm happy with my performance and the new techniques I used successfully out there."
Both Gustafsson (15-1) and Rua (21-7) did not expect the fight to go the distance. Yet it did despite the pair exchanging huge lefts and rights throughout. The difference was Gustafsson's ability with his legs, which staggered Rua at times with kicks and knees. The second round was especially fruitful for the 6-foot-5 Gustafsson, including a knee to the face followed by a right-hand midway through the round that staggered Rua.
It was the second straight time that Gustafsson went the distance and likely sets up a title chance for the Swede against either current champion Jon Jones or Chael Sonnen. Jones and Sonnen are expected to meet for the title in late April.
Gustafsson won decisively on the judge's scorecards 30-27, 30-27, 30-26.
The opener of the main card saw welterweight Matt Brown (18-11) win his fourth straight fight with a devastating 1-2 combo midway through the second round that flattened Mike Swick (15-5).
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