Good cause or not, Kim Kardashian is feeling the results of a boxing match for charity that she took part - it left her with a black eye!

The reality-show princess, 29, more used to being pampered than pummeled, took to the ring for The Dream Foundation on Tuesday night, Nov. 4, with other members of her family. But though the gloves never came off, she walked away with more than the humbling feeling of having been handed a defeat despite three days of training.

"My girl was a good sport, but she was tough!" Kardashian wrote on her Web site on Wednesday. "I knew I had to do it for charity, since that's what it was all about, but man, my girl could throw a punch! Look at my black eye!!! "

Still, she got it easier than little brother Rob, who got pounded by a noticeably bigger guy.

"When Rob stepped in the ring to fight, his opponent was at least 25lbs (11.3kg) heavier than him, even though the organisation had assured us that they were screening the people we were fighting against and that they would be within 5lbs (2.3kg) of our weights!" Kardashian wrote. "At one point Rob's mask fell off and when he put his hands down he got hit in the face and ended up in hospital with a concussion. Rob's a strong guy and can definitely hold his own, but he wasn't expecting to get hit after his mask had fallen off! This guy just got really down and dirty!"

But Kim said all the bruises were worth it.

"At the end of the day, we did this for charity and that's what counts. Rob is doing fine now and my black eye will be gone soon... I hope," she wrote. "You can try to bring the Kardashians down... but we're a strong family. A concussion and a black eye can't hold us down!"