PHILADELPHIA -

An investigation is underway into the beating of a man wearing Detroit Lions gear after the team played the Philadelphia Eagles in Philadelphia.

Police said the 33-year-old victim, Paul, was assaulted while leaving Lincoln Financial Field after Sunday's 34-20 Eagles victory over the Lions.

Paul moved from Detroit to Philadelphia two years ago. He is an avid Lions fan and was proudly wearing a Barry Sanders jersey and a Lions hat.

"I've never experienced being knocked out. It's the first time I've ever experienced going through that. So when I woke up I was confused. I didn't even realize I was in a fight right away," said Paul, who did not want his full name used in this story.

He said six men in Eagles jerseys approached him as he was nearing the subway to go home and at least two of those men attacked him. He was knocked to the ground. Another fan rushed to help him as the rowdy Eagles fans took off.

"Once there was like 3-4 swings and pushes, I kind of realized what was going on. I knew that this was my shot to defend myself. I did go into defense mode," said Paul.

Police department spokeswoman Officer Jillian Russell said investigators are looking for surveillance video that could help identify the suspects.

"We're outraged and we don't condone this at all," said Philadelphia Police Cpt. Laurence Nodiff.

Detroiters love their teams but Paul says fans in the city of "Brotherly Love" are downright mean.

"I had a lady pushing a stroller talk trash to us. I had an 8-year-old kid with his dad walking in the morning say something to us, and the dad laughed. We had an officer drive by and roll down the window and scream out at us. We had a semi truck pull over, get out and scream at us. It's different here," he said.