Two Brooklyn straphangers were punched in the face hours apart in two unrelated incidents late last month, cops said Sunday. 

A 22-year-old woman was slugged around 3:40 p.m. March 28 after getting into a dispute with a male stranger on a southbound 4 train, police said.

Cops had no further details on the incident — which happened as the train was approaching the Utica Avenue-Crown Heights station.

The attacker bolted, they said.

The victim suffered pain and swelling to her eye. 

About two hours later, a 61-year-old man was on the southbound R train platform at the Bay Ridge Avenue station when he got into a fight with another man, which cops said was over a lighter. 

At some point during the squabble, the suspect punched him in the face and took off. 

The victim was taken to NYU Langone Hospital—Brooklyn, where he was treated for pain to his head and neck. 

Both suspects were captured on surveillance released by cops late Sunday, and remained on the loose Monday morning.