Liverpool dominated from the first minute to the last and Dunk said every Brighton player would admit they weren't good enough on the day.
However, despite the disappointment of the final-day defeat, Dunk also reflected on a successful season as Albion finished 15th.
Dunk said: "I'll be brutally honest, I thought we were awful today.
"It was a typical end of season game where we've got nothing to play for and they have and it showed.
"I was so disappointed walking off the pitch and I think every single one of us would admit we weren't good enough today.
"That's the most frustrating thing to go out on a great season like that.
"It's disappointing but credit to them, they did what they do and killed the game off in the first half and we've just got to enjoy our summer now and come back next year."
Dunk added manager Chris Hughton reflected on the whole season in his post-match team talk and said: "The gaffer talked about the season as a whole. It's credit to the boys, we've had a great season and that's the main thing we've got to look at.
"But I'm one of those who will look at the game now and it wasn't good enough but overall we've been very good this year."