Justin Bieber Throwing Punches At a Boxer, Not a Fan This Time

Justin Bieber is keeping his hands up to date in a boxing gym -- even though recent evidence shows his jab is pretty sharp.

Bieber hit up Ten Goose Boxing in Van Nuys, CA on Friday for a few rounds of sparring. This is the same gym where he's worked the mitts with his pal Floyd Mayweather in the past.

Justin might feel the need to work on his skills after his run-in with a fan in Spain last week. The fan, who hooked up with JB's left fist, would say it's not necessary. At all.