Eagles Fan Berates Female Packers Supporter At Playoff Game, 'Dumb C***'

11:00 AM PT -- The Eagles tell TMZ Sports they're looking into the incident.

A man decked out in Philadelphia Eagles gear berated a female Packers fan on Sunday -- clapping in her face and calling her a "c***" -- and at least part of the ugly scene was captured on video.

The confrontation happened at some point during Green Bay's disappointing 22-10 playoff loss to Philly at Lincoln Financial Field ... when Packers content creator Alexander Basara says he and his fiancée were trying to catch the game from some upper deck seats.

In footage Basara posted to his X page late Sunday night, you can see after refs changed a ruling on the field -- a man in a green Eagles jacket got in Basara's fiancée's ear ... clapped a few times, and yelled, "Short of the goal line, you dip s***!"

"It's not a touchdown!" he added.

When Basara tried to interject in an apparent effort to defuse the situation ... the Eagles fan can be heard on camera screaming, "She's an ugly dumb c***!"

"Turn around!" he later yelled. "Watch the game, bitch!"

Unclear how the altercation ended -- or really, how it even began -- but Basara claimed in a post on his social media page that it was all "unprovoked." He's now asking his followers for help identifying the man.

"I hate that my fiancé had this happen simply cheering for her team," he wrote.

While the Packers' season is now over, Philadelphia will host another playoff game against either the Rams or Vikings at the Linc on Sunday.