Donald Trump held it in for about 18 hours before finally letting loose over “Saturday Night Live”’s parody of his media-bashing news conference.

Trump vented about the skit — which included a torrent of urine-related jokes by impersonator Alec Baldwin — around 5:45 p.m. Sunday.

“.@NBCNews is bad but Saturday Night Live is the worst of NBC. Not funny, cast is terrible, always a complete hit job. Really bad television!” he tweeted.

Earlier, incoming White House press secretary Sean Spicer also blasted “SNL,” telling FOX News’ “Media Buzz” that the long-running comedy show was little more than a “left-wing hit piece.”

“’Saturday Night Live’ used to be funny,” Spicer complained.

“It’s gone from being funny to just bad. Those aren’t jokes. They’re inappropriate … I think for a lot of people, regardless of your political persuasion, that’s not what you’re tuning in for.”

Trump’s swipe at “SNL” followed earlier tweets in which he accused Democrats of being poor losers and predicted he’ll draw further support from their ranks.

“The Democrats are most angry that so many Obama Democrats voted for me. With all of the jobs I am bringing back to our Nation, that number..will only get higher. Car companies and others, if they want to do business in our country, have to start making things here again. WIN!” he wrote.