We just happened to be staying in an RV resort where there were hundreds of Show Dogs. The park was near an arena where a national dog show was being held.
I was walking my medium sized dog (not pit bull) with a leash around the park. Normally she is good around other dogs but once in awhile a dog will set her off. We were approaching a beautiful champion Akita. My dog lunged and the leash broke (the connection at the collar broke). Luckily the owner of the Akita was quick and was able to stop my dog. The Akita probably would have won the battle. I apologized and explained what happened. He said he had just finished grooming the dog and took it for a walk before heading over to show it.
Check those leash connections...replace the leash if it looks worn.