smug

He had a smug look on his face after winning the race by a large margin.

(Chinese) 在以巨大优势赢得比赛后，他脸上露出了自鸣得意的表情。

Don't be so smug about your success; you had a lot of help from others.

(Chinese) 别对你的成功这么沾沾自喜，你得到了很多人的帮助。