In the book by Malcom Gladwell "Underdogs, Misfits, and the Art of Battling Giants" it speaks about how underdogs in either sports or life in general have the advantage. It speaks about how there isn't the pressure that you're expected to win something or do well. People expect you to lose and have no expectations.
One good point he makes is that you can always perform with a free spirit in your head. That free spirit is a critical part of success because it means that you are less tense and stressed out, therefore causing you to perform better. One example he used was in college basketball. The "March Madness" tournament is the biggest college basketball tournament that always has a few major upsets. The 15th seed underdog beating a top seed is always a common occurrence every year in the tournament. Those top seeds freeze up when they are down by a few points with not much time remaining. They're psychological game isn't as strong as their physical game therefore causing them to panic and then lose to a team they should beat. It happens a lot in sports, because as the old saying is "you have nothing to lose".  Personally, I play tennis competitively in tournaments and I always enjoy playing seeded players when I'm not seeded because I know I have nothing to lose. And that's always when I play my best because I have a free state of mind.
In conclusion, Gladwell's idea of underdogs really having the advantage is very accurate. They don't always win, but it allows them to play more freely, with less to lose. I've had that feeling of being the underdog and although people may not know you because you are the underdog, it's a great way to start by making a name for yourself and beating the higher ranked opponents.