Take a good look at that man singing "Ghostbusters" next to you at the karaoke bar. It just might be Bill Murray.

During a recent night out at New York City's Karaoke One 7, a few lucky fans were pleasantly surprised when Murray knocked on the door of their private room and sat down for a few songs.

Mike, one of the revelers, tells theCHIVE.com he spotted Murray at the bar earlier that evening and invited the quirky actor to join his crew, but he didn't expect the star to follow through.

"About 15 minutes later we get a knock on the door... IT'S BILL F@#KING MURRAY!" says Mike, who shares photos of the experience with theCHIVE. "We were all shocked, of course, but at that point we were already pretty trashed so the party just kept going."

Murray, who was accompanied by a female companion, ordered the gang another round of drinks ("some French liqueur made by monks," says Mike), before belting out a few tunes.

"The high point was when Bill and I sang a duet of an Elvis song called, 'Marie's the Name,'" says Mike. "Random I know, but so was the night."

But maybe it wasn't quite so random.

In 2008, the New York Post reported that the "Lost in Translation" star – who had just split from his wife – had turned into quite the party animal, hitting on women at bars throughout the city, crashing hipster house parties in Williamsburg, Brooklyn, and being spotted exiting apartment buildings in the early morning hours.

"It was surreal, I was like, 'Why are you here, talking to us?' said Sophie Ellis, who had Murray suddenly join her table and buy her party two bottles of champagne at Manhattan pub the Half King. "He was very gentlemanly, even though he looks quite grumpy — like a granddad."

Mike agrees that hanging with 60-year-old Murray can be fun, if not a little freaky.

"As you can imagine it was all pretty surreal. Something I will never ever forget…Viva Bill Murray!"