What makes the underdog story so fascinating is that he or she is expected to go down, yet for whatever reasons defies the odds.
In Grand Slam tennis, underdogs don't just defy the odds once, twice or thrice.
They have defy the odds seven times before they can call themselves a Grand Slam champion.
Let's look at the 20 best tennis underdog stories in Grand Slam open era history.
The list isn't exhaustive, so if I've missed out, feel free to comment below.