'90210' Star Ian Ziering Viciously Attacked by Bikers on Hollywood Blvd.

Ian Ziering got jumped by a bunch of bikers running amok in Los Angeles — a horrific moment caught on camera … and one helluva lousy way to end his year.

The ‘Beverly Hills, 90210’ star fell into the crosshairs of several assailants Sunday who were cruising down Hollywood Blvd. on a variety of motorized mini bikes and weaving in and out of traffic … including, it seems, Ian’s vehicle — which we’re told may have been hit.

You can see Ian hop out of his car after one of the bikers seemingly catches his attention, possibly from a collision … and the altercation erupts in a violent brawl, all seen on video obtained by TMZ.

Check it out … Ian starts wailing on the guy in question, but soon — he gets ganged up on by the others … who begin to whoop on him mercilessly as he tries to make a run for it. Like we said, the cilp is absolutely bananas … especially considering this a well-known actor.

We’re told this beatdown ended with Ian getting back in his car and driving off … ditto for the bikers, who got the hell out of there. It doesn’t appear cops were called — so you could say it was left in the streets. Not to make light, but this pretty is ‘Sharknado’-coded, no?