'TMZ Hollywood Sports' -- Ex-Boxing Champ Reveals ... Why I'm Stalking Hayden Panettiere's Fiance

He's stalked him by land ... and also by sea ... but now, former boxing champ Shannon Briggs is talking to us about WHY he's hell-bent on fighting Hayden Panettiere's fiance.

Make sure to check out the brand NEW episode of "TMZ Hollywood Sports" on Reelz -- every weekday at 8pm ET, 5pm PT.