Justin Bieber has been hanging out at Coachella 2018 enjoying the music and the parties.

But on April 14, the music and art festival's laid-back atmosphere took a serious turn.

Broadimage/REX/Shutterstock

TMZ reports that Justin, 24, punched a man in the face then threw him against a wall at a Coachella party on Saturday after the man grabbed a female partygoer by the throat and refused to release her.

"Justin was talking to some people when a guy walked in, spotted a woman... and went ballistic," TMZ writes. "Sources at the party say he appeared to be on drugs -- and it looked as if the woman may have been his ex-[girlfriend]."

After the man grabbed the woman's throat, "Justin and his friend started screaming at the guy to let her go, but he only screamed back, 'Go f--- yourself'... maintaining his grip," TMZ writes.

Natt Lim / Getty Images for Coachella

That's when Justin -- who a day earlier was at Coachella posing for selfies with the Walmart yodeling kid, Mason Ramsey -- took a swing and shoved him, allowing the female to get away.

TMZ reports that the man was then kicked out of the party -- which was also attended by Patrick Schwarzenegger -- and arrested after police were called.

At one point after he was made to leave, the man was seen chasing an SUV, hitting it and screaming Justin's name because he thought the pop star was inside it, TMZ reports.

Matt Baron/REX/Shutterstock

Meanwhile later the same day, one of Justin's exes -- model and Instagram star Chantel Jeffries -- was spotted on the Coachella festival grounds getting close to The Weekend, who famously dated the Biebs' ex Selena Gomez in 2017.

Photos published by DailyMail.com show The Weekend, 28, with his arm around Chantel, 24, laughing and smiling as they walked around the Coachella VIP area in Indio, California, the evening of April 14 with drinks in hand.

Chantel made headlines in early 2014 when it was revealed that she was with Justin the night he was arrested on DUI and drag racing charges in Miami.

Back in 2015, Justin and his entourage were kicked out of Coachella after getting into an argument with festival staff while trying to watch Drake's performance. Justin was reportedly put in a chokehold by security during the heated exchange.