Justin Bieber put on one heck of a show at his most recent concert … no, he’s not touring again — he performed at a ceremony for a billionaire’s wedding.

The singer-songwriter arrived in Mumbai yesterday for Anant Ambani and Radhika Merchant‘s sangeet, a pre-wedding ceremony filled with singing and music … and, instead of DJ, the couple brought the Biebs!

Check out the clip … JB hits the floor, dancing by himself before pulling a girl up and having her twirl a couple times in front of the crowd.

More video is out online too BTW … featuring Justin singing classic tracks like “Baby” and getting the crowd jumping — definitely a wedding celebration these guests won’t soon forget.

Of course, the happy couple’s well-known at this point for having some of the world’s biggest stars in attendance … remember, back in March, Rihanna performed at a pre-wedding ceremony for Merchant and Ambani — so the star power has stayed high throughout the long pre-wedding.

As for Bieber … it’s a rare performance. He’s appeared onstage sporadically since canceling his “Justice” tour after he revealed he was diagnosed with Ramsay Hunt Syndrome.

His last big gigs have been a guest spot at Coachella and a show during NHL All-Star Game Weekend in Toronto … so, only the biggest stages get the guy back on the mic live.