Fegan and Knight had been in the bottom two after audience and judges' scores for Monday's Motown night performances were combined. In a last-ditch effort to remain in the competition, they danced a jive simultaneously before judges Len Goodman, Carrie Ann Inaba and Bruno Tonioli, and Inaba voted to save Knight, while Goodman and Tonioli voted for to keep Fegan in the competition.
Knight's performances have landed her at or near the bottom of the score board for the much of the competition, but her spirit and her natural style of dance have earned consistent praise from the judges.
"I am just amazed at this journey," Knight, standing next to her pro dance partner Tristan MacManus, said after the final result was announced. "It's been absolutely extraordinary, I learned so many things, found so many friends and family and I'm just overjoyed."
Earlier in the show, during a short video in which the competitors talked about how demanding the competition had been so far, Knight said she was dedicated to doing well.
"I'm not a quitter. You all are going to have to throw me out," she said.
Tonight's show features live performances by Boys II Men and Natasha Bedingfield.
In addition to Fegan, returning next week to compete are "Extra" co-host Maria Menounos, NFL player Donald Driver, Welsh opera singer Katherine Jenkins, telenovela star William Levy and actor Jaleel White.
Tennis star Martina Navratilova, actor Jack Wagner, talk show host Sherri Shepherd and singer Gavin DeGraw have already been booted this season.
The final three celebrities and their pro dance partners will battle it out for the mirror ball trophy.