The 49ers beat the Lions 25-19 yesterday, and immediately after the game, Niners coach Jim Harbaugh and Lions coach Jim Schwartz almost got into a fight.

Harbaugh was jumping up and down celebrating, and he gave Schwartz a pretty hard handshake at mid-field, and sort of dismissed him. And he also allegedly shouted a swear word.

And Schwartz apparently took offense because he ended up CHASING Harbaugh down the field, while the players and coaches kept them from going at it.

Harbaugh tried to accept some of the blame for it, but not really. He said, "I was really revved up. That's on me. The handshake was too hard."

But they both definitely lost their cool. Here's the video:

It's actually the second time Harbaugh has had an issue with post-game handshakes. He and former USC coach Pete Carroll got into it back in 2009 when Harbaugh was coaching at Stanford: