Boxing champion Carl Froch has retained his two super-middleweight world titles after a controversial finish to his fight with George Groves.

The English 36-year-old was knocked down in the first round, and was well behind on points when he launched an assault on 25-year-old Groves in round nine.

The fight was stopped when Froch landed a big barrage of punches on his younger opponent. 

"He caught me with a good shot, but that should never have been a stoppage," Groves told Sky News.

Froch said it was the right decision, but asked for a rematch to "sort it out". 

"George had his head low and I had a free shot and the referee had a split-second decision to make. It was dangerous and he had to put the safety of the fighter first."