Many people thought his first hit song was just a flash in the pan, but he went on to have a successful career.

许多人认为他的第一首热门歌曲只是昙花一现，但他后来却拥有了成功的职业生涯。

We need consistent performance, not just a flash in the pan.

我们需要持续的表现，而不仅仅是昙花一现。