The stacked actor, who plays vampire Emmet Cullen in the `Twilight` films, has revealed he accidently punched his fellow actor Jackson Rathbone - who plays his adopted vampire brother Jasper Hale - leaving him unconscious while shooting a fight scene for the third movie in the franchise.
Speaking at the official `Twilight Saga: Eclipse` press conference in London on 01.07.10, Kellan said: "We had fun times with the fights scenes. We had an oopsy daisy moment when I hit Jackson and knocked him out a little bit during one of our scenes."
Director David Slade quickly corrected the 25-year-old model-turned-actor, saying: "You knocked him completely out!"
Kellan replied: "He was a trooper he got up and started gurgling his words and mumbling - it was cute. He has become a mischievous little Jackson lately, who thinks he can take the world. But it was really great times after that."
Last night, thousands of fans turned out for the premiere of `Eclipse` in London`s Leicester Square.
A host of cast members dazzled on the red carpet, including Kellan, Ashley Greene, Nikki Reed and `Eclipse` newcomer BooBoo Stewart.
However, main stars Robert Pattinson, Kristen Stewart and Taylor Lautner did not make an appearance on the red carpet leaving many `Twilight` fans disappointed.