The party's not over until Shia LaBeouf spits water on Marilyn Manson.
That was the strange scenario that played out at the opening of the L.A. outpost of The Box nightclub on Friday night, an eyewitness tells Life & Style exclusively.
Before the performance even started, the "Transformers" actor, 25, "seemed wasted" as he sat in a designated area with his date, presumably girlfriend Karolyn Pho, and rocker Manson.
"Shia picked up a water bottle and shot a mouthful of water all over his date's legs," says the eyewitness. "Then he put more water in his mouth and started spitting it all over his tablemates, including Marilyn Manson."
Although Manson tried to calm the actor down by offering him a fist bump, LaBeouf only grew more out of control.
"All of a sudden, Shia started shouting at his date and getting visibly angry," adds the eyewitness.
He then decided it was time to leave and "lunged" through the very thick crowd. "They tried to hold him back, but he kept struggling through.
"Shia had to climb over people and tear himself out of the grasp of various strangers who were trying to keep him from going crazy."
Once he broke free and bolted out the door, his panicked date chased after him. The two never returned.
"Marilyn looked shocked and annoyed, but stayed seated," adds the eyewitness.
"It was so insane -- he just had a total meltdown right in front of everyone. It was completely out of control. He was so angry and physical."