In the main event of UFC Fight Night 25 in New Orleans, Ellenberger handed Shields the quickest loss of his career with a 53-second TKO. The loss comes just three weeks after the death of Shields' father and manager, Jack Shields.
"It's unbelievable – Jake Shields is a world champion, so I can't explain how I feel right now," Ellenberger said. "Just keeping the pressure – that was the strategy coming in here. I came out with the W and it feels great."
Ellenberger (25-5, 5-1 UFC) landed a left and a right, then moved in on Shields, tying him up. He threw one right knee, then a second that landed on the button. Shields dropped to the canvas, and Ellenberger pounced and landed several shots from Shields' back before the fight was stopped.
Shields (26-6-1, 1-2 UFC) appeared to go limp when the knee landed, then continued to look finished when he wasn't covering up from Ellenberger's strikes. But the former Strikeforce middleweight champion said after the fight he didn't think it should have been stopped.
"I'm just frustrated," Shields told Joe Rogan. "I got hit with a good hit. I thought I could still fight, but it is what it is. I thought I could keep fighting, but the ref thought it was time to stop it. There's nothing I can do."
Ellenberger's win gives him five straight in the welterweight division. Champion Georges St-Pierre defends his title against Carlos Condit next month, and a fight between BJ Penn and Nick Diaz could determine the next contender after Condit. But Ellenberger's quick win over Shields will have his name in consideration.
Ellenberger, though, said he won't think about where he should fall in the division.
"It really doesn't matter where I think I'm at. It's up to the UFC, and whoever they tell me to fight, I'm going to fight," Ellenberger said.
Ellenberger also said he was surprised he won the fight as quickly as he did. It was the fastest fight in Shields' career, and obviously his fastest loss. It was only the second time in Shields' career that he has been stopped, and the first time since 2000.
"I definitely could have envisioned myself winning this fight – but not that quick," Ellenberger said. "It happened fast, but I trained hard for this fight and I knew I was ready. ... The ref's job is to stop the fight, so I'm going to go until he stops me."
In the co-main event, Court McGee returned for the first time in 11 months and beat Dongi Yang by unanimous decision. McGee, the Season 11 winner of "The Ultimate Fighter," was rocked in the third round, but held on to get the victory, winning by scores of 30-27, 29-28 and 30-28.
And Alan Belcher returned for the first time in 16 months following a pair of eye surgeries and stopped Jason MacDonald in the first round. The win came just about an hour away from Belcher's Biloxi, Miss., home.
"It felt great, man – the crowd definitely gave some energy," Belcher said. "Even up until tonight, I was uncertain what I wanted to do. I was nervous as hell going into this training camp. I missed the feeling, and I feel like I can definitely continue down the path I was on and go for a title shot. I've got a feeling the title shot's going to come faster than I want it now."
Also on the main card, featherweight Erik Koch won his fourth straight with a unanimous decision victory over Jonathan Brookins.
UFC president Dana White after the fight handed out $55,000 bonus awards to four fighters. Ellenberger took the Knockout of the Night, delivering the night's only KO or TKO. TJ Waldburger, one of four submission wins, won Submission of the Night. And Lance Benoist and Matt Riddle won Fight of the Night for their preliminary card slugfest, won by Benoist in his UFC debut by unanimous decision.