Prompted by calls from his frightened girlfriend, a Madison man went to his apartment, found an intruder, punched him and held him until police arrived, according to police.
Officers responded to the apartment on Odana Lane at 2:12 p.m. Friday.
A 32-year-old man told police he and his two friends went to his apartment after his girlfriend called concerned about several young men outside their apartment, followed by a ring of the doorbell and rattling of the backdoor.
Police said the man and his friends arrived as one of the suspects entered the apartment through the kitchen window while two others waited outside for the door to be opened.
When the boyfriend arrived, the two men outside fled and the man inside tried to run but was punched a couple times and detained by the boyfriend.
Juan P. Lara, 18, of Fitchburg, was treated at a hospital for head injuries before being arrested on suspicion of burglary and for a probation violation.
One of the other two men is described as Hispanic, in his early 20s, 5 feet 9 inches tall and weighing 150 pounds. The other is described as 18 to 25 years old, 5 feet 5 inches to 5 feet 8 inches tall and weighing 130 to 150 pounds.