Britney's Las Vegas Femme Fatale Photo Album

Britney Spears and Nicki Minaj tore it up Saturday night in Vegas!

Our photographer there, front row at the concert, tells us: "It was the most amazing night of my life. Britney was amazing -- the sets and the costumes and the dancers and the whole production. I can't believe Britney's been at it this long and she's still at the top!"

That says it all, folks. Check out our massive gallery from Britney's Las Vegas Femme Fatale concert with opening act, Nicki Minaj ...