Substitute Asa Hall scored a dramatic 89th-minute winner to maintain the bottom club's faint hopes of survival after Luton's Mark Bower had cancelled out Ryan Bennett's opener.
The Hatters are still 12 points from safety, but Harford said: "I keep believing we can do it and I've told the players now there's 10 games left and it's 10 cup finals. We're looking forward to the Johnstone's Paint Trophy but every league game is more important to us than the trophy final.
"The win was needed but I thought it was deserved especially after our first-half performance. It was a sucker punch to go 1-0 down but the pivotal moment was the equaliser before half-time. We weren't great in the second half but we got what we deserved in the end.
"When teams come here to stick bodies behind the ball and run the clock down it bemuses me but we kept playing the right way and got what we deserved.
"There was a lot of tension out there because the fans and the players know the predicament we're in and that's why I picked an experienced side to deal with the situation."