gaining on

to get closer to sb/sth that you are chasing 接近，逼近（所追逐的人或物）

In some places he was quicker and at others I’d gain on him…
他在某些地方比我快，而我会在其他地方追上他。

The Mercedes began to gain on the van.
那辆奔驰开始逼近小货车。