The team is looking to 'defend' its national title. [=to win the national title again]
As a U.S. senator, it is my responsibility to 'defend' [='uphold'] the Constitution.
She successfully 'defended' her championship. [=she won the championship again]
(..) A lake lies between us and that mountain. - We have no way to cross it. - So then we go around. The Orcs will run us down, as sure as daylight. We've no weapons to defend ourselves. Bind his leg, quickly. You have two minutes. Do it again... ...and you're dead. Excuse me... (..)2013 The Hobbit: The Desolation of Smaug