Wladimir Klitschko's boxing brain will beat Anthony Joshua's brawn, says his brother Vitali

Wladimir Klitschko's boxing brain will help him to beat the brawn of Anthony Joshua, according to the Ukrainian's brother Vitali.

Joshua faces Klitschko at Wembley on April 29 in what the British boxer has described as a fight which could define his entire career.

The 27-year-old, who is unbeaten in 18 professional bouts, boasts an impressive physique but is vastly inexperienced when compared to his opponent.

Klitschko has lost just four of his 68 fights and older sibling Vitali is convinced next month's showdown will result in the first blemish being added to Joshua's record.

"Many people think muscles are important in boxing," Vitali told Sky Sports. "It's not. Everything is here, in the head.

"He's much more focused right now than many years ago. I hope he knows from his focus, from his concentration, that this fight depends a lot and that's why everyone expects a great fight.

"Of course we expect a good performance from Wladimir and yes of course Wladimir has to be the winner," insisted the 45-year-old, who is a former heavyweight champion.

Joshua's IBF title plus the IBO and WBA belts will be on the line. The fight will be watched by a record crowd of 90,000 after Mayor of London Sadiq Khan paved the way for an additional 10,000 spectators to be added to the bill.

Joshua has previously fought at England's national stadium on the undercard of Carl Froch's victory over George Groves in 2014 but Vitali believes greater arena experience will give his brother another advantage.

"Wladimir has already big experience of fighting in an arena. He's used to fighting in a stadium, pressure from the crowd, from attention.

"It will be something new for Joshua and nothing special for Wladimir," he added.