Our 5-year-old boy loves to challenge us when we try to discipline him. We would ask him not to do something and he would go right ahead and do it. Eventually it escalates and he starts to scream, hit, and occasionally spit. We would give him a timeout but he would continue to do the same thing and get out of the timeout spot. We eventually resorted to sitting him on top of a chest of drawers so that he has to stay in timeout.
However, these methods don't work in the long run. He continues to misbehave, talk back, hit, etc. When we had a play date with one of this friends, he got mad because the kids couldn't agree to the rules of a soccer game and he threw the soccer ball at him. Another time he actually punched the other kid in the back.
Also, we've resorted to taking things away, such as toys and screen time.
I also want to add that he hates losing...i.e. he loves to win (and hates to lose)...at games, probably between all social interactions...which I think includes when he gets disciplined. A lot of times when he loses it would set off bad behavior.
I'm at my wits' end and want to see if this forum can give some advice.