I have found in the past I was too much of a Gentleman when it came to playing against a Woman, Finishing heads up against the opposite sex always put me at a disadvantage because I was trying to be nice and there is no room for nice in Poker!
Whenever I found myself heads up against a man is was a fight to the death, with no punches pulled, and I wanted to destroy them. Women however needed my protection and I couldn't understand why I would start to lose even with a massive chip lead over them, They on the other hand wanted to break me and prove that Women are better than Men, and it didn't take me long to realise my mistake.
You have to treat every player you are up against as the Enemy, nothing to do with their Gender, as they are all the same, they are out to destroy you, and you have to fight back.
Once you can do this, everything falls into place, and you can beat even the most beautiful Women players, They are just another opponent!