in my "sport" ( Chess ), ties happen all the time. We still have champions. To win a tournament they have to win or tie the most games.
Many other sports have a series of games to determine who wins... baseball, basketball come to mind. Winning one game does not make you the winner. You have to play and win 4 games out of 7 or something.
There is a large element of luck to win a single game, especially in overtime. I think the 49ers were the best team in Football this year, as evidenced by the number of other teams they played ( good teams ) and completely dominated. One of their best defensive players did something to his Achilles tendon running onto the field. Somehow injured his foot so badly that he could not continue to play. Bad luck. Wasn't even during a play.
That might well have cost them the game as his replacement allowed a couple of crucial passes. Dre Greenlaw was one of about 3 or 4 "defensive superstars" on the 49ers. Bad luck.
The 49ers lost a bad luck game... I don't think they are going to be riots and burn down San Francisco ( or Santa Clara ) tonight.