Police arrested a 23-year-old man Tuesday night after he allegedly punched and knocked out his girlfriend in the elevator of a Waikīkī hotel, then left her there unconscious.

The woman, 22, told police she was arguing with her boyfriend before he hit her about 7 p.m.

Police said hotel security personnel found the woman in the elevator. She was taken to a nearby hospital and regained consciousness there, police said.

The boyfriend was arrested at 2005 Kālia Road on suspicion of second-degree assault.