Super-middleweight champion Robert Stieglitz admitted he had some sympathy for Yuzo Kiyota after the Japanese challenger boxed on for two rounds despite blood pouring down his face from a cut eye.

Stieglitz picked up the 45th win of his career from 48 professional bouts as he defended his WBO belt with a technical points win over Kiyota on Saturday.

A cut over Kiyota's left eye in the eighth round eventually saw the fight stopped after 15 seconds of the 10th and Stieglitz was awarded the fight unanimously 99-90, 100-89, 99-90 by the three judges.

The referee ruled the decisive cut came from a clash of heads, rather than a punch, which meant the fight was decided on points rather than Stieglitz being awarded a technical knock-out.

This was the 29-year-old Kiyota's first professional bout outside of Japan and he was taken to hospital straight after the fight to have the deep cut over his left eye stitched up.

Kiyota was docked a point in the fifth round after repeated warnings for dropping his head and was later warned for using his elbow.

Stieglitz was in control from the third round onward and admitted he was concerned for Kiyota as the blood flowed down the challenger's face.

"He couldn't really see much anymore and I had a bit of sympathy," said the 32-year-old as Kiyota skipped the post-fight press conference to go to hospital.

"It was almost unfair to box against someone in that situation.

"He had some interesting, unusual movements and at the start of the fight, he was very dangerous."

Kiyota, who raised a few eyebrows by turning up to the pre-fight press conference wearing a surgical mask, is left with a record of four defeats, 21 knockouts in 23 victories.

Stieglitz's coach revealed why the blood had stirred some sympathy in the champion.

"He gets really sickened by the sight of blood. There was a lot of it and that was pretty uncomfortable for him," explained Stieglitz's coach Dirk Dzemski.

Stieglitz has already turned his attention to another bout against compatriot Arthur Abraham, who he beat in March to regain the WBO title he lost to Berlin-based Abraham in August 2012, his only defeat in the last four years.

"I would like to box against him again, but there have been no phone calls and I don't know if he wants to box against me," said Stieglitz.

Abraham faces Namibia's Willbeforce Shihepo in Schwerin, north-east of Berlin, on August 24 and any future bout between Abraham and Stieglitz would be the third fight between the pair.