A man is wanted by police for smashing a glass bottle over the head of a 22-year-old woman, knocking her unconscious, at a popular Williamsburg bar.

Police said the unidentified suspect walked up from behind the woman and assaulted her at about 3 a.m. Feb. 23 at Union Pool, which is located at the corner of Union and Meeker avenues.

The woman was hospitalized with a concussion, pain and bruising, police said.

Her attacker fled and, as of early Tuesday, was still being sought by cops.