The non-league side defeated the Premier League outfit 1-0 away from home to progress to the fifth round of the competition, courtesy of the 26-year-old's goal.
"Yes, it was better than sex," The Sun quotes him as saying. "To score a goal in a game like this was unbelievable. I have to be careful as my missus could read this!"
Luton will face Millwall in the fifth round, and Rendell is confident of beating the Championship team.
"I don't think it was the draw everyone hoped for," he said. "But it's a home tie at Kenilworth Road and no one is going to fancy coming down here.
"The crowd make a lot of noise so we are definitely looking forward to a winnable tie. There have been a lot of shocks in both cups this year so the FA Cup is still wide open."
Rendell joined Luton in June 2012.