Donald Trump Jr. got into a heated clash Thursday with Jim Acosta as he joined the Twitter army of people, including his father, mocking the CNN correspondent for a video that inadvertently made the case for a border wall.

Acosta, known for his dramatic flourishes that get under the skin of President Trump and for getting into fights with top Trump officials, posted the video during a visit to the border, coinciding with the president's trip.

“Here are some of the steel slats that the president’s been talking about,” Acosta said while reporting in Texas and touching a wall slat. “But as we’re walking along here, we’re not seeing any kind of imminent danger.”

CNN'S JIM ACOSTA MOCKED FOR ACCIDENTALLY PROVING THAT BORDER WALLS WORK

“There are no migrants trying to rush toward this fence.”

Acosta then declared there was “no sign of the national emergency that the president has been talking about” and it was “tranquil” near him. He captioned the video, “I found some steel slats down on the border. But I don’t see anything resembling a national emergency situation.. at least not in the McAllen TX area of the border where Trump will be today.”

The tweet was met by a chorus of mockery, which included Press Secretary Sarah Sanders and even Trump himself -- who adopted Twitter user @neontaster’s game of prefacing any Acosta tweet with the words “Dear Diary.” They argued Acosta didn't see an emergency because he was at a section of the border protected by the kind of barrier Trump supports.

Trump Jr. then piled on, thanking Acosta for proving Trump’s point, “and simultaneously creating one of the best self-own videos ever!!!”

Acosta soon responded: “It’s a little strange Don. You guys seem to be saying the current measures in place are working. Does that mean your dad should reopen the government and get federal employees back to work? #byebye.”

CNN'S JIM ACOSTA DOUBLES DOWN ON HOW SAFE BORDER IS BEFORE TRUMP FIRES BACK

Trump Jr. responded: “I know this might be hard for you to comprehend Jimbo, but the reason why all of Twitter has been mocking you today is because you were at a part of the border WITH A WALL. So yes, of course it was working. Replicate that across the border & we’ll all be safer. #RealNews #ByeBye”

To put a not-too-subtle finish to his point, the president’s son later retweeted a meme called, “Spotted: Jim Acosta playing golf earlier today” and showing a man with a CNN logo for a face getting run over by a Trump-like driver in a golf cart.

“Bye, go home to mommy,” the Trump voiceover says.

Fox News’ Brian Flood contributed to this report.