Man in surgery after Perth fight

An 18-year-old man is undergoing emergency surgery after hitting his head on the ground following a fight in Perth's northwest.

A 24-year-old man is due to appear before Perth Magistrates Court charged with grievous bodily harm on Saturday.

Police say both men were travelling in the same vehicle on Friday about 9.30pm before they got out of the car and a fight ensued in Alkimos.