Peterson, who has not fought in 14 months since testing positive for synthetic testosterone, stopped Holt in the eighth round at the DC Armory.
Peterson, who was forced to cancel his planned rematch with Amir Khan last May following the test, twice knocked down Holt with a pair of solid right-handers.
He followed up with a flurry of blows in the eighth, forcing referee Tony Weeks to stop the bout with 1min 42secs gone.
Victory for Peterson sees him improve his record to 31-1-1 with 16 knockouts, while Holt's record now reads 28-6 with 16 knockouts.
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