It was a staggering way to end a 10-game run without a goal and allows Berbatov to join former United striker Andy Cole, Alan Shearer and Jermain Defoe in the elite group to hit five.
"I can't believe it. I scored five in a game but it happened," Berbatov said.
"I have scored that many before but it was a long time ago back home in Bulgaria.
"Today I did it in the Premier League. To stand next to people like Cole and Shearer is a great honour."
It took Berbatov just 71 seconds to open his account, adding another before the break and then scoring three more times after the restart.
"The first goal was the most important," he added.
"It gives you the confidence to play.
"As a striker, people do tend only to look at the goals you score.
"I am more concerned with how I play but today was all about goals for me."