WordNet (r) 3.0 (2006):

walkaway
    n 1: an easy victory [syn: runaway, blowout, romp,
         laugher, shoo-in, walkaway]

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "walkaway":
   Cadmean victory, KO, Pyrrhic victory, ascendancy, cakewalk,
   championship, conquest, easy victory, grand slam, knockout,
   landslide, landslide victory, mastery, moral victory, picnic,
   pushover, romp, rout, runaway victory, subdual, subduing, success,
   total victory, triumph, victory, walkover, win, winning,
   winning streak