The angry fan turned out to be the girlfriend of Papis' competitor Mike Skeen -- both men had made contact and spun off the track during the race.
"This crazy lady comes shouting at me, and I had no idea, didn't even understand her, she just started shouting," Papis told ESPN.com after the incident. "And all the sudden, she took a full hand -- and she slapped me so hard. I'm not kidding. My jaw got dislocated and my left ear is still ringing, big time."
"What do you do? You don't hit a lady," the Italian said. "I was in disbelief. Complete disbelief. If she would've closed her hand it would have been a bad punch, because she hit me so freaking hard. I went to [Skeen] and said, 'I guess we know who's the man in the family here, because the guy didn't even have the [guts] to talk.'"
Skeen's girlfriend wasn't the only person to lash out at Papis on Sunday. A "rival crew member" reached into the car as Papis was unbuckling, before members of his team pushed him away.
Papis continued the discussion on Twitter later.
"That deal was only between me and #6 driver we could have solved it alone ...but I guess he needed some ...help !!!!" he wrote.
And by the way .... Even if she deserved I will not hit a Lady and it was just between 2 racers not between me and him no other that is it— Max Papis (@maxpapis) September 2, 2013
I didn't know about the slap, but that was relatively tame considering he barged our trailer later and tried to pull her down the stairs in front of a NASCAR official and several members of our team. She has bruises to prove it. Those are the facts from my perspective.
Here's the GIF, courtesy of Jalopnik:
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