Spotted by my brother as we were watching the fight in HD. Check out the jacket of the guy on the left side of the screen.
(Click the image to see a larger version of the picture.)
Namco-Bandai games does own the trademark to the name 'Pac-Man'. So perhaps they approached him and, instead of suing for copyright or whatever, just asked for some kind of sponsorship?
Or maybe the guy with the jacket is just a huge Tekken 6 fan. Who knows. Interesting bit of trivia, nonetheless. I never noticed it at all while watching the fight; the quick eyes of my brother easily spotted it during the fight introductions.
If you manage to catch the HD video of the fight, you'll see that the TEKKEN 6 patch is also on the other side of the guy's jacket. (so both the left and right shoulder of the jacket he's wearing has 'TEKKEN 6' on it.) I've tried to take screenshots of the other patch but it always ends up blurry.
EDIT: Here's the other side of the guy's jacket. Unmistakably, Tekken 6 is some kind of sponsor for Manny Pacquiao/Team Pacquiao.