The Russian lost to Timothy Bradley in a fight-of-the-year contender in March but has now become a world champion with a devastating display from the eighth round.
It was a fairly even fight through seven, although the challenger looked to be on top. The fight swung massively in his favour when he sent the 33-year-old down twice in the eighth.
The American took severe punishment in rounds nine and 10, forcing the referee Tony Weeks to step in a bring a stop to the contest before the start of the 11th round.
Alvarado had shown plenty of heart but Provodnikov was just too strong, with the scorecards later revealing that the judges had the Russian up 90-90, 96-92 and 97-90 at the time of the stoppage.