Get The Better Of Meaning

(transitive, idiomatic) To gain an advantage over.

Example: 1859, George Eliot, Adam Bede, ch. 28,
  Adam said, "My temper got the better of me, and I said things as wasn't true."
1922, James Joyce, Ulysses Episode 16
  Though this sort of thing went on every other night or very near it still Stephen's feelings got the better of him in a sense though he knew that Corley's brandnew rigmarole on a par with the others was hardly deserving of much credence.
2005, Eric Pfanner, "With Characteristic Fortitude, Britons Carry On," New York Times, 8 Jul. (retrieved 2 Sep. 2008),
  Many people returned to work a bit anxious, they acknowledged, but grimly determined not to let terrorists get the better of them.
  He got the better of him early in the match, but finished by losing.