"There was no boxing ability in there," Fury said. "I didn't show nothing. All I showed was heart."
Cunningham (25-6, 12 KOs) has lost two of his three heavyweight bouts since moving up from cruiserweight last fall. He said he has no plans to move back to the weight class where he was a two-time world champion. Fury (21-0, 15 KOs), from Manchester, England, advanced to meet Kubrat Pulev, and the winner of that bout will meet Wladimir Klitschko in a title fight.
A 4-1 underdog, Cunningham shocked the crowd as he knocked down Fury in the second round with a right hook. After the first round, a clearly agitated Fury shoved Cunningham well after the bell.
"He knew he couldn't outbox me, he knew he couldn't beat me like that," Cunningham said. "So he took it to the alleyways."
Cunningham stunned Fury in the fourth with an overhand right. Early in the fifth, Fury was deducted a point for a head butt.
Fury responded to the deduction by controlling the rest of the round. He danced to the arena's music between rounds and fought with confidence. Cunningham's pace slowed; fatigue had set in. Fury was simply too big.
By the middle of the seventh round it was clear that a knockout was near. A right hook from Fury made it happen.
"I was just hunting him down, like a lion on a deer," Fury said. "And he was running away and I hunted him down. Bang. Struck cold. Goodnight."
On the undercard, North Philadelphia's Karl Dargan improved to 13-0 with a technical knockout of Edward Valdez. Valdez was unable to continue past the second round because of an injured right hand. Dargan started turning his strong defense into swift combinations before the fight was halted.
"I was like a ghost," Dargan said. "I was hitting him, but he couldn't see me to hit me back."
Contact Matt Breen at firstname.lastname@example.org. Follow on Twitter @matt_breen.