Undefeated boxing prodigy Jose Benavidez Jr. -- who's 25-0 as a pro -- was shot while out on a walk in Arizona early Tuesday morning ... but we're told he's expected to survive.

FYI, the 24-year-old Top Rank fighter is a rising star in the sport -- and recently chalked up a high profile victory over Francisco Santana on the undercard of the Crawford vs. Postol fight in Vegas.

Sources tell us ... Benavidez was out walking one of his pets near his home in Phoenix when he was approached by an unknown man who pulled out a gun and shot him in the leg.

The Phoenix PD confirms the shooting and says the victim was transported to a nearby hospital with non-life threatening injuries.

However, one source with knowledge of the situation tells us Jose's injuries pose a serious threat to his boxing career.

So far, no arrests have been made.

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