MANNHEIM, Germany -- Wladimir Klitschko retained his WBA and IBF heavyweight titles with a sixth-round knockout of Francesco Pianeta of Italy on Saturday.
The Ukrainian was never troubled by Pianeta and he finished off the unbeaten southpaw with a right-left combination. Pianeta stayed down before attempting to continue, but there was no point in delaying the inevitable and referee Ernie Sharif ended the bout 2 minutes, 52 seconds into the round.
"Francesco tried, he has a fighting heart," Klitschko said. "He's a positive example in boxing. I'm sure he's learned a lot and that he has a great future ahead of him."
Klitschko rocked Pianeta inside the first 30 seconds, knocked him to the canvas with a straight right down the middle in the fourth, and again with a left blow in the fifth.
"I'm very disappointed and sad," said Pianeta, a cancer survivor who lives in Gelsenkirchen, Germany. "I can't say anything. It wasn't my day. He's the world champion. It wasn't enough. That was rubbish today."
The fighters worked together briefly last year and Klitschko tried to be kind to his former sparring partner.
"Francesco wasn't easy to box. He punched with the hardest punches I've ever felt. Luckily they didn't hit me," Klitschko said.
Pianeta, who was spirited but clearly out of his depth, dropped to 28-1-1 (15KO), while the 37-year-old Klitschko improved to 60-3 after his 52nd knockout.
Vitali Klitschko, who holds the WBC belt, said he had no worries ahead of his younger brother's 23rd championship bout: "My brother was very strong. Francesco has a big heart. You have to pay him respect."
Next up for the younger Klitschko is a likely bout with mandatory challenger Alexander Povetkin of Russia, the "regular" WBA champion after Klitschko was elevated to "super champion" status.