The man had climbed a 20-metre-high (65ft) crane at a construction site, and police were called to the scene.
Ifzal Zaffar, who is of Pakistani descent, duly climbed up too and addressed him in their shared language.
The man agreed to come down, and was taken to hospital.
Constable Zaffer, who also speaks fluent Cantonese, said he was simply following his training.
"I used the techniques we learned at the academy … I think he felt safer knowing that I could talk to him in his own language," he told Apple Daily.