Check this out:
http://www.chess.com/tournaments/help.html#tiebreak
The more tie break points you get, the stronger the opponents you defeated were. If you defeat one guy, you get 1 tie break point for each point of his score, and if you draw, you get half of his score.
Maybe you only defeated one opponent, but that opponet had 5 victories. So you get 1 score point, and five of tie break. If I defeat only 1 guy like you have done, but my opponent just had 3 victories, I´ll get 3 points of tie break, so you are ahead (from me).
Wait- did you look at my tournament statistics?
I'm playing in a tournament, and right now, my score is tied to a fellow participant in the same group.
However, I was placed ahead because I have a higher tie break.
That made want to ask: how do tie breaks work?