LAS VEGAS » With a pair of rear naked chokes that finished two celebrated champions, Nate Diaz and Miesha Tate both accomplished the improbable in a pair of sport-shaking victories at UFC 196.

Diaz forced Conor McGregor to tap out with 48 seconds left in the second round Saturday night, ending the Irish superstar’s 15-fight winning streak in a non-title bout.

Tate won the UFC bantamweight title at the MGM Grand Garden Arena, locking Holly Holm in a choke that rendered the champ apparently unconscious with 90 seconds left in the fifth round.

Diaz (20-10) was battered and bloodied for the first 1 1/2 rounds by McGregor (19-3), the UFC 145-pound featherweight champ and pay-per-view star fighting at 170 pounds on short notice.

Diaz, who took the fight less than two weeks ago, abruptly changed the bout with an electric series of punches that wobbled the previously unshakable McGregor. When McGregor tried a takedown, Diaz quickly forced him to tap out on the ground.

“I thought I landed with some good punches that got him off (his game),” Diaz said in one of his few post-fight comments not punctuated by exuberant profanity. “I started off slow, but I’m faster than anyone later on. My jiu-jitsu is always there for me.”

Earlier, Tate (18-5) became the third 135-pound champion in UFC history by beating Holm (10-1), the woman who knocked out Ronda Rousey in November. Holm appeared to be out cold when Tate finally released her from the choke to celebrate.

“Not many people wouldn’t tap out,” Tate said. “She went out like a champion.”

The back-to-back upsets thrilled a sellout crowd and a huge pay-per-view audience, but they also threw two potential wrenches into the UFC’s plans for the upcoming year. McGregor is widely expected to fight in the main event at UFC 200 in July, while Holm’s next fight was supposed to be her rematch with Ronda Rousey, who has already beaten Tate twice.

The main event was the greatest moment in the career of Diaz, a pugnacious veteran from a notorious fighting family in Stockton, California. Diaz had lost three of his past five fights and was just 5-5 since 2010, but his size and power abruptly finished McGregor, who had boasted of his plans to hold championships in multiple weight classes.

The loss was McGregor’s first since November 2010, and it put a blemish on the loquacious Irish face of the UFC and the best-paid fighter in this rapidly growing sport.

“These things happen,” McGregor said. “I learn, I grow. I’ll face it like a man, like a champion.”

McGregor is still the UFC’s 145-pound champion, but he agreed to fight Diaz at the welterweight limit when 155-pound lightweight champion Rafael Dos Anjos dropped out of his matchup with McGregor due to a foot injury.

McGregor set a new UFC record with his $1 million disclosed purse for this fight, but that’s only a portion of the wealth bestowed on a champion who gets a percentage of pay-per-view sales and other undisclosed bonuses. He expected a comfortable win over Diaz, comparing the veteran to a gazelle about to be eaten by a lion.

Instead, McGregor got bit.

“I felt good in the first round, but I was inefficient,” McGregor said. “He was efficient. I wasn’t. I took a chance. It didn’t work out.”

The penultimate fight at UFC 196 was a thrilling clash of styles, and Tate fought until the waning minutes before finally using her superior ground game to outstanding effect.

“I feel like we had a great game plan,” Tate said. “I had to be patient. She’s very dangerous. She’s capable of catching anyone at any moment. She’s a very calculated fighter.”

For 4 1/2 rounds, Holm appeared to be winning her first fight since she dethroned Rousey with a stunning head-kick knockout in one of the sport’s biggest upsets.

Although Tate controlled the second round on the ground and got close to a finish, Holm picked apart Tate with punches for the other three rounds before the fifth. Tate knew her advantages were on the ground, so she tried multiple takedown attempts that were defended well by Holm.

Everything changed when Tate finally landed a desperate takedown attempt and got Holm’s back with 2 minutes left.

Holm fought desperately to get out, but the veteran wrestler sunk in a choke that she didn’t let go until she was the champion.

“It wasn’t the right move to shake her off my back,” Holm said. “It was stupid, and I should have fought it off more. When you’re up against a wrestler like that, of course that threat is there for a takedown, and you have to recognize it.”

Tate was overwhelmed after finally reaching her longtime goal. She hasn’t lost a fight since 2013 but realized this might be her last chance to fight for the belt.

“I’m freaking out inside,” Tate said. “I knew I had to play it cool with her, because she’s so good.”