When you say that the victory was a `cakewalk’, what you mean is that it was very easily achieved. You didn’t have to put in too much of an effort; you won without really having to work hard.
Examples: Given your experience, getting the job should be a cakewalk *The first couple of rounds of the tournament should be a cakewalk.
The `cakewalk’ was a form of entertainment among African Americans. Well-dressed couples that took part in this competition were made to walk around a cake. The pair that performed this task most gracefully was awarded a prize. In most cases, the prize was the cake itself; the winner used to `take the cake’. Later, the word `cakewalk’ was used to refer to a popular form of dance.