IRVINE, Calif. >> The Fight for L.A. finally has some punch.

A handful of skirmishes broke out today when the Los Angeles Chargers visited the Los Angeles Rams’ training camp for the teams’ second joint practice in five days.

The fights mostly arose between the Chargers’ offense and the Rams’ defense during a lively scrimmage.

In the first and best scrap, Rams cornerback Trumaine Johnson threw a punch at Chargers receiver Dontrelle Inman before Rams cornerback Nickell Robey-Coleman pushed Inman to the ground — and Chargers receiver Keenan Allen responded by body-slamming Robey-Coleman.

Even veteran Chargers quarterback Philip Rivers chipped in with some trash-talking of the Rams’ defenders during the workout, but Rams cornerback E.J. Gaines’ bloody face was the only noticeable result of the short-lived brouhahas.

The players and coaches left UC Irvine with the first on-field instance of bad blood between two franchises currently competing for the hearts and minds of Los Angeles’ football fans after moving to town one year apart.

“We’re definitely building a nice little rivalry with the Rams,” Chargers running back Melvin Gordon said. “That’s what I got out of today.”

The franchises have co-existed peacefully in the seven months since the Spanos family announced the Chargers’ intention to join the Rams in Stan Kroenke’s lavish Inglewood stadium complex, which will open in 2020.

The Chargers also moved north with a bold advertising campaign built around a “Fight for LA ” slogan, and they actually released a new video from the campaign earlier Wednesday.

That fight hadn’t really materialized until the teams got together for a workout lasting more than two hours. They are holding their training camps 5 miles apart in Orange County.

“It’s a fun experience being out here,” Rams quarterback Jared Goff said. “I’m sure there’s a little bit of a rivalry among the fans with both LA teams now, but it was a good day today, and it was a lot of fun to see both teams’ fans out here.”

The teams also held a joint practice last weekend at StubHub Center, the Chargers’ new home stadium, without anything approaching a fight.

Everything changed in Irvine, where Johnson and Inman set off the festivities with a scrap after the whistle.

“He probably landed (a punch) on my helmet, which is kind of nothing,” Inman said of Johnson. “I think that’s stupid. If you break your hand, then what? But nah, I think it got real intense.”

Johnson, the Rams’ highest-paid player, indeed threw a punch at Inman, and Robey-Coleman flattened Inman as the third man in. Johnson said the scuffle arose from Inman leaving his hand in Johnson’s facemask for far too long.

“Where I’m from, if somebody initiates it, you’re going to finish it,” Johnson said. “But it was a fun competition. … I’m from Stockton, (California) and the Stockton came out in me. At the end of it, he got in my face, and I’m not going to let anybody disrespect me.”

The intensity and feistiness likely were secretly thrilling to both coaches, who used the joint practice to shake their teams out of the preseason doldrums with their exhibition openers looming this weekend.

Sean McVay and Anthony Lynn both expressed relief that nobody got seriously hurt in the workout.

“I liked the energy,” McVay said. “Going against another quality team is something that’s going to be helpful for us going forward. … (Fights) are a good learning opportunity for us as a team, about keeping that composure in scrimmage situations.”

The teams won’t play each other during the regular season, but they will face off in a preseason game at the Coliseum on Aug. 26.

Neither team expects any bad feelings from this workout to linger — and most players were back to casual friendliness by the time they wrapped up this practice at dusk.

During their first year of cohabitation, the clubs will spend their weeks about 90 miles apart on opposite ends of the sprawling Los Angeles metroplex. After their preseason showdown, the Fight for LA will be mostly an advertising slogan and a point of debate for fans.

The Rams’ faithful made their feelings known in Irvine with rude chants directed at the Chargers. Talkative Chargers cornerback Casey Hayward had a running dialogue with hecklers during one drill, but it was mostly in good fun.

“I just saw a lot of good competition out there,” Lynn said. “I didn’t encourage the fighting, but I was pleased with the intensity.”