J Lo, Enrique & Sting Perform Greatest Wedding Concert Ever for Russian Billionaire's Son

Jennifer Lopez, Sting and Enrique Iglesias all sharing the same stage FOR A WEDDING ... is no big deal if you're the son of a Russian billionaire marrying your 20-year-old bride!

This is insanity, but yeah ... Russian oil tycoon Mikhail Gutseriev forked out a fortune to get all 3 performers to play his son's Moscow wedding -- and the photos and videos inside put any Hollywood bar mitzvah to shame.

Here's what you need to know -- bride Khadija Uzhakhovs' dress reportedly cost about $1 MILLION, they had a 9-tiered cake that stood at least 10 feet tall, and there was nothing less than Bentleys or Rolls-Royces at the valet.

Looks like J Lo ran through a bunch of the songs she does in her Vegas show. Check it out though, audience participation was limited ... due to the language barrier.