Jennifer Lopez Scores Big Vegas Payday ... Residency Now Looms

Jennifer Lopez passed the "Vegas Residency Test" with flying colors on New Year's Eve, and in the process scored more than $400K.

Our Vegas sources tell us ... Lopez raked in $410,000 for her NYE performance at Caesars Palace, plus she gets back end. Even though the show was sold out, the venue only netted slightly more than $600K.

It's still good, and our sources say the point of the gig was to see if Lopez was a sufficient draw for a full-on residency.

To put Lopez's payday in context, Britney makes around $475K a show with her new contract.

We're told Caesars was pleased.