Klitschko KOs Leapai in 5th

Wladimir Klitschko KOs Alex Leapai in 5th round to retain WBA-IBF heavyweight titles

Germany Boxing Klitschko

IBF, WBA, WBO and IBO champion Wladimir Klitschko from Ukraine, right, punches his Australian challenger Alex Leapai during their heavyweight world title bout in Oberhausen, western Germany, Saturday, April 26, 2014. (AP Photo/Frank Augstein)

APTOPIX Germany Boxing Klitschko

IBF, WBA, WBO and IBO champion Wladimir Klitschko from Ukraine, right, punches his Australian challenger Alex Leapai during their heavyweight world title bout in Oberhausen, western Germany, Saturday, April 26, 2014. (AP Photo/Frank Augstein)

Germany Boxing Klitschko

IBF, WBA, WBO and IBO champion Wladimir Klitschko from Ukraine celebrates knocking out his Australian challenger Alex Leapai during their heavyweight world title bout in Oberhausen, western Germany, Saturday, April 26, 2014. (AP Photo/Frank Augstein)

Germany Boxing Klitschko

IBF, WBA, WBO and IBO champion Wladimir Klitschko from Ukraine, right, knocks down his Australian challenger Alex Leapai during their heavyweight world title bout in Oberhausen, western Germany, Saturday, April 26, 2014. (AP Photo/Frank Augstein)

OBERHAUSEN, Germany (AP) -- Wladimir Klitschko toyed with Alex Leapai and knocked him out in the fifth round to retain his four heavyweight belts on Saturday.

Klitschko, taller with a longer reach, controlled the fight at will, scoring with left jabs and straight rights with hardly any opposition from the Australian challenger.

Leapai went down when he was hit with a left-right combination. He got up but Klitschko put him away for good with 58 seconds left in the fifth.

Klitschko recorded his 53rd KO in 62 wins, with three defeats. Leapai dropped to 30-5, with three draws.