Aberdeen manager Jimmy Calderwood admitted he was ashamed of his team's performance after 5,000 fans travelled down to Dundee to support them.
"We came with high hopes but we didn't perform," said Calderwood.
"Defensively we were very poor, though United played very well. We thought we could get back into it but straight after half time the game was finished.
"We hardly strung two or three passes togther and there was no quality service for the strikers."