BERN, Switzerland (AP) — Vitali Klitschko retained his WBC heavyweight title with a unanimous decision over previously unbeaten Kevin Johnson of the United States yesterday.

The 38-year-old Klitschko kept Johnson against the ropes for much of the fight but landed few heavy shots to hurt the 30-year-old challenger.

Johnson proved a durable opponent and did his best work with counterattacking straight left jabs, though without managing to rock Klitschko who has never taken a standing count in his career.

Klitschko (39-2, 37 KOs) was making a third successful defense of the belt he reclaimed in October last year after a four-year break to recover from injuries.

He opted to take the fight just 11 weeks after beating Cris Arreola, another unbeaten American who did not come out for the 11th round of their bout in Los Angeles.

Johnson, the WBC’s sixth-ranked contender, experienced his first professional defeat in his 24th fight.

At 2.02-metres (6-foot7) and 112 kilogrammes (247 pounds), Klitschko took a size advantage of 11 centimetres (3 1/2 inches) and 2kg (4lbs) into the ring.

Johnson opted for defensive tactics, inviting the champion from Ukraine in the second round to come at him.

Klitschko aimed mostly head shots but a succession of overhand rights found Johnson turning away in defense.

The champion’s right cheek was marked in the fourth round, and Johnson connected with a left hook in the sixth.

But Johnson failed to mount many combinations and Klitschko kept winning rounds with steady jabs, more big rights and an occasional straight left.

The fight heated up in the 11th when Klitschko responded to Johnson’s taunting hands-spread gesture with a flurry of blows.

In the final round, Johnson pointed at his chin to goad Klitschko into another attack, and the bout ended with the American finally trading punches in the center of the ring.

The two squared up after the bell and Johnson was ushered back to his corner by Klitschko’s young brother Wladimir, the IBF and WBO champion who works in Vitali’s corner.