An easy victory; winning comfortably or being overwhelmingly likely to win.
相手が練習不足だったので試合は楽勝だった。
The opponent hadn't practiced enough, so the match was an easy victory.
格下のチーム相手なら楽勝だろうと油断したら負けた。
We got careless thinking it would be easy against the lower-ranked team, and lost.
彼の実力差を考えれば勝利は楽勝だ。
Considering the gap in ability, victory will be a breeze.
Something very easy to do; 'piece of cake' or 'walk in the park' (colloquial).
この問題は基礎だけで解けるから楽勝だよ。
This problem can be solved with just the basics, so it's a piece of cake.
英語のレッスン？僕にとっては楽勝だ。
English lessons? They're easy for me.
本番前の練習はうまくいったし、本番も楽勝だろう。
Practice went well, so the actual performance should be a breeze.