Jennifer ran through her "All I Have" show at Planet Hollywood on Monday night (January 18), and even though the front row was loaded with familiar faces -- like BFF Leah Remini, her mom and kids -- she nailed the routine.
Video from the VIP gig shows J. Lo hitting her marks (like a Fly Girl should) -- and, apparently, really singing instead of lip syncing.
Jen's performing on Britney Spears' off days in the same theater, and shows for the public begin Wednesday night.
Photo: Getty Images