Jersey Shore star Ronnie Ortiz-Margo was busted early Friday for allegedly striking on-again, off-again girlfriend Jen Harley, chasing her with a knife and ultimately forcing cops to tase him,  according to a new report.

Ortiz-Magro was placed in handcuffs after the incident, which occurred shortly after 2:30 a.m. at an Airbnb the pair was renting in Los Angeles, law enforcement sources told TMZ.

He allegedly slapped and punched Harley, prompting her to run out of the house and scream for help, according to the report. Then, according to the report, he allegedly ran after Harley with a knife in one hand — and, disturbingly — also holding their 18-month-old daughter Ariana.

At some point he dropped the knife and locked himself and the tot in the house, according to the report.

Responding officers needed to break down the door out of concern that Ariana could be in danger, TMZ reported. The “Jersey Shore” star still did not comply — prompting officers to take him down with a taser, the gossip site reported.

Ortiz-Magro was taken to a hospital to be checked out and will be booked as soon as doctors say he is well enough, according to the report.

Neither Harley nor the baby suffered major injuries, though Harley did have visible marks on her face, the outlet reported.

Earlier in the day, the couple told TMZ they were back together. They’d just called it quits last month after Harley accused her Jersey Shore beau of spending time on a boat with another woman over the Labor Day weekend.

The couple, who share 1-year-old daughter Ariana Sky, have had a rocky relationship from the start. Harley was arrested in May for allegedly attacking Ortiz-Magro during an argument on New Year’s Eve at a Las Vegas club.

The Clark County District Attorney’s Office decided to drop the alleged domestic battery case against Harley in July.