When she played a Spice Girl classic, there was nothing Victoria could do but join her onstage.
As Sporty belted out "2 Become 1" Victoria became Posh again - if only just for a moment - to sing and sway along, and she even threw in a few signature peace signs for good measure.
Despite the mini reunion, the pair are the only two members of the band who have said they won't be joining fellow members Emma Bunton, Melanie Brown and Geri Halliwell for an official reunion.
"The other two b-----s didn't want to do it," Mel B told James Corden on The Late Late Show.
"Let me correct that. My other two fellow lovely ladies — you know Victoria [Beckham] is busy with her great fashion line, Mel C is doing her own album — so they politely declined but gave us their blessing."