a flash in the pan
idiomPart offlash
a flash in the pan — idiom
1. A sudden success that only lasts for a very short time and is unlikely to happen
1.idiom
Definition
A sudden success that only lasts for a very short time and is unlikely to happen again.
Example
The band's first album was a huge hit, but they turned out to be a flash in the pan.
Many critics thought the actor would have a long career, but his early success was just a flash in the pan.