Ireland's Andy Lee stopped Matt Korobov in the sixth round to win the vacant WBO middleweight title in Las Vegas.

Lee was the underdog to prevail against the unbeaten Russian, but the 30-year-old landed a huge right hand that gave him the opportunity to win his first world crown.

The opening two rounds went to Korobov, but Lee nicked a tight third with a heavy shot before the former leading amateur restored order to frustrate the Irishman.

However, after the two traded blows in the sixth, Lee landed a punishing right hook that wobbled Korobov, and allow him to step in with over a dozen unanswered punches which gave the referee no option but to wave off the fight.

Lee is scheduled to defend his belt against Billy Joe Saunders in the spring.