noun

a person who has surpassed all rivals in a sporting contest or other competition.

a champion hurdler

winner,title-holder,defending champion,gold medallist,prizewinner,cup winner,victor,conqueror,victor ludorum,titlist,champ,top dog,number one

verb

vigorously support or defend the cause of.

he championed the rights of the working class and the poor

advocate,promote,plead for,hold a torch for,defend,protect,uphold,support,back,espouse,ally oneself with,stand behind,stand up for,take someone’s part,campaign for,lobby for,fight for,battle for,crusade for,take up the cudgels for,propose,sponsor,vouch for,second,stick up for,throw one’s weight behind,plug