American Julian Jackson knocked out Britain's Herol Graham in the fourth round Saturday night to win the vacant World Boxing Council middleweight championship.

Graham, the British middleweight champion, dominated the first three rounds, scoring with a variety of combinations and frustrating Jackson, who was missing wildly with his punches.But midway through the fourth round, when it appeared Graham was in control, Jackson suddenly delivered a short right hand that sent Graham to the canvas.

He was counted out by Referee Joe Cortez of Atlantic City, N.J. It took over five minutes for Graham's handlers to get him back on his feet.

Jackson's victory gave him the WBC middleweight crown, vacant since Sugar Ray Leonard retired earlier this year. He also currently holds the World Boxing Association light middleweight crown.

Jackson scored his 34th straight knockout in raising his career record to 42-1, with 39 knockouts.

The 31-year-old Graham took his third defeat against 43 wins, going to the canvas for the first time in his career.