Charlie Sheen is calling out L.A. Mayor Antonio Villaraigosa ... claiming he was flat-out LYING when he said he spent ONLY 3 minutes with the actor in Cabo -- Charlie says the Mayor hung with him for hours, chatting it up and drinking with a bunch of hot chicks.
Mayor Villaraigosa told NBC 4 L.A. ... his encounter with Charlie was no big deal, saying, "I had a three-minute conversation and took a picture with him, that simple.... I take a picture virtually every single day, 50 times."
But Charlie says the Mayor is shoveling BS. Charlie tells TMZ ... the picture was actually shot in Charlie's hotel suite at Hotel El Ganzo, where Charlie had just opened his bar, Sheenz earlier in the evening.
What's more, Charlie says the Mayor hung out in the suite for WAY more than 3 minutes. Charlie says, "I memorize 95 pages a week, so the last thing that I am is memory challenged. We hung out for the better part of 2 hours, discussing his L.A. roots, his poignant bullet campaign as well as his 3 AM lawn-watering tactics."
Charlie continues, "He's a terrific guy, a great Mayor and he can drink with the best of 'em: Me. Quite a memorable night indeed."
You'll recall ... when Charlie introduced Slash and another band earlier in the evening at his bar, he hurled a homophobic remark. After TMZ got the video, we contacted Villaraigosa but he had no comment.
The Mayor's office told TMZ they would have "no further comment."