Motocross legend Brian Deegan was arrested for an alleged bar brawl on Saturday ... the same day his best friend sustained injuries in a bike crash that would later take his life.
Deegan was arrested for suspicion of assault after a throwdown at the iLounge bar in Orange County, where he allegedly sliced open a patron's face by hitting him with a glass.
The same day, Brian's best friend, Jeremy Lusk, sustained major injuries during a botched back flip at a freestyle motocross event in Costa Rica. Lusk never regained consciousness after the wreck -- and passed away on Tuesday.
Motocross Champ's Bad Week Gets Worse
2/12/2009 4:03 PM PST BY TMZ STAFF
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