Before the show, Ashlee Simpson and Pete Wentz held court at the VIP bar. Later the newly engaged – and expecting! – couple sang along as West performed "Can't Tell Me Nothing" and got to their feet for his emotional rendition of "Hey Mama" (a tribute to his late mother Donda).
Simpson, who has kept coy about her widely-reported pregnancy, snacked on Sweet Tarts candy and stuck to bottled water.
Also in the house? A very pregnant Gwen Stefani, who sat on a couch in the VIP area while her husband, Gavin Rossdale, mingled with the rest of her No Doubt bandmates.
Chris Brown slipped into the auditorium just before Rihanna, his rumored girlfriend, took to the stage as West's opening act. And although he played it cool – never dancing or singing along – he kept a wide grin on his face throughout her performance.
Meanwhile Serena Williams and the rapper Common stepped out together once again, but avoided any signs of a PDA while they mingled backstage.
Several solo stars were also spotted at downtown L.A.'s Nokia Theater, including Ryan Phillippe and Jamie Foxx.