The TV presenter, who pulled out of last year's show with a leg injury, lost out in the skate-off to Melinda Messenger.
Todd Carty scored only 7.5 points for his performance to 'Every Breath You Take', but was saved again by the public vote.
Underwood and his professional partner Melanie Lambert got a mixed reaction from the judges, totalling 18.5 points for their routine to Prince's 'Kiss'.
"I had a brilliant time," said Underwood following his exit. "It was great to come back and skate with Mel again. We had a good laugh."