People have been doing that in football in Europe forever. I remember a number of old world cup games completely ruined by people running the clock.
Of course, the score ended up being just that towards the end of the game, and then the players on both teams just stood still and passed the ball between themselves running down the last 8 minutes or so of the clock.
I do believe in football (soccer for americans) a referee will intervene if players are obviously stalling (e.g. by not playing, or the goalkeeper just holding onto the ball) but they can just go back and forth for a bit.
Probably also happens in boxing and other time related sports.