Los Angeles- MULTIPLE meltdowns marred Grammy Awards night, from Sly Stone’s walkout and Mariah Carey’s pout-out to filmmaker Brett Ratner’s near pass-out.

During the all-star tribute to Sly and the Family Stone, fallen funk god Stone – barely singing and listlessly bobbing his mohawked head – drifted offstage mid-song.

Our insider reports hunchbacked Stone, 62, vomited in the wings: “He was overcome with stage fright. He left the building on his own. No one saw him out. No one knows where he went.”

Carey, meanwhile, who won a few awards but blew the biggest ones, refused to come out of her dressing room post-show, sulking over losing the Album of the Year Grammy to U2. “She ended up back at her hotel with a small group of friends,” a spy told PAGE SIX, making only a drive-by to her own after-party hosted by supermarket billionaire Ron Burkle.

Lucky for her. At Burkle’s, “Rush Hour” director Ratner caused a one-hour traffic jam after paramedics and a fire truck were called in response to his full-blown panic attack – caused by an argument with his date – in front of the Spanish-style mansion. Cops came later and had the music turned off.

“Ratner was complaining of shortness of breath while leaning by the VIP check-in desk,” a witness told The Post’s Braden Keil. “My heart is racing,” the witness overheard him repeating.

So was Barry Manilow’s. Overwhelmed on the red carpet, the “Muppet”-like crooner had earlier become “claustrophobic,” relates a witness, and fled inside the Staples Center, refusing interviews.

Sheryl Crow, who brought her manager as her date in the wake of her Lance Armstrong split, also declined press interviews. At the Palms – where many celebs fled post-haste from the Staples Center for Universal honcho Doug Morris’ viewing party – she sat with consoling friends.

Country lovebirds Garth Brooks and Trisha Yearwood skipped out of the show after 15 minutes, hanging outside with cops on folding chairs and waiting for their car to arrive. The two were secretly engaged on Dec. 10. “I greeted guests in a red dress and then switched to a white one,” Yearwood told us. “She looked like an angel,” cooed Brooks, who thanked cops for “everything.”

Already moving on to the next awards, presenter Matt Dillon, walking the red carpet, told our Paula Froelich, “I don’t have a date for the Oscars yet. But you’re presentable.”