A dinner guest who witnessed Britney Spears’ “outburst” at a Los Angeles restaurant detailed the pop star’s “rough” night.

In an exclusive interview with Page Six, Jeff Sneider recalled that he and a friend arrived at Blue Dog Tavern in Sherman Oaks at around 7 p.m. PT on Wednesday night. Soon after, a woman “behind sunglasses” and two of her friends walked in, but he did not immediately realize it was the Princess of Pop.

“The woman sat down and proceeded to make a lot of woofing or barking noises and just throw a lot of outbursts,” he alleged on Thursday.

“It wasn’t really until she took off her sunglasses that we realized, ‘Oh no, this is Britney Spears.'”

Sneider — who has been an entertainment reporter for 20 years — alleged that Spears “kept standing up and sitting down and moving around the restaurant.”

He also claimed that at one point while she was standing up, she may have “forgot to put down her silverware” and was holding a knife.

“I wasn’t threatened or anything like that,” he clarified. “But when she eventually left, I turned around and was like, ‘Holy s—t that was crazy!’ to the entire section.”

Sneider alleged that one woman sitting in their section felt threatened, and said of Spears, “She had a knife and came toward me. I thought she was going to stab me.”

Although Sneider doesn’t think that the Grammy winner had any violent intention, he said she was “definitely a nuisance to sit next to at dinner.”

He also alleged that the two other people in Spears’ party “tried to coax her back into her seat” throughout the dinner, but were unsuccessful in their attempts.

“They definitely tried their best to get a handle on her but she was obviously a handful,” he claimed.

Sneider did not witness Spears — who recently finished rehab treatment — drink any alcoholic beverages at the restaurant.

He said at one point Spears “lit up a cigarette inside the restaurant” and that staff told one of the people she was with that she had to put it out.

As for what the superstar ate, Sneider claimed that she “picked at” her burger and french fries and that she and the bodyguard “fed each other some fries.”

“I never got the impression they were asked to leave,” he told us, though he alleged there was a lot of food “left on the table and underneath the table” and that Spears “definitely made a mess.”

“She was in rough shape last night and it was hard for me and my friend to carry on a conversation.”

On Thursday, Spears’ rep shut down claims that his client potentially posed any danger during the alleged episode.

“This is completely blown out of proportion. Britney was enjoying a quiet dinner with her assistant and bodyguard. She was simply telling the story about how her dog was barking at the neighbors,” her rep said in a statement to Page Six Thursday.

“At no point did she put anyone in danger with a knife,” they continued. “She was cutting her hamburger in half.”

On Thursday morning, TMZ reported that the singer “was raising her voice, screaming and even barking at times” in a “chaotic” scene during her Wednesday night meal.

Shortly after her return home, an insider told Page Six that the “Slave 4 U” songstress was “doing really well” and “excited to start afresh.”

“Rehab was a great opportunity for her to ground herself,” the source told us.