The Dark Blues had captain Gary Irvine sent off just 20 minutes into the derby encounter at Tannadice but nevertheless took the lead through a superb Ryan Conroy strike in the second half.
The visitors appeared poised for a famous victory until the final minute when Michael Gardyne popped up to equalise for the hosts.
He said: "It's a case of mixed emotions. We didn't do all that well with the 10 men.
"It was hard but we still kept going to get the equaliser.
"I have to praise the players for that. They never gave up.
"We had enough chances to win but it wasn't to be.
"We're still in the running for the top-six place but we need more wins at home."