A 25-year-old Waianae man, who suspected his girlfriend was cheating on him with a 40-year-old man, beat and kicked the man unconscious in Nanakuli, police said. 

The suspect surrendered to police yesterday morning at 9:20 and was booked on suspicion of second-degree assault.

Police said he showed up at the victim’s home and demanded the man come outside about 12:30 a.m. Sept. 12. 

The two argued and the younger man struck the other man in the face and head, knocking him down, police said. He allegedly struck the victim several more times and kicked him in the head as he lay unconscious. 

The victim sustained a facial and skull fracture.