WireImage 1 / 14

Nick Lachey and his wife, Vanessa Lachey, may have the same birthday, but it was all about the former 98 Degrees frontman during a star-studded birthday bash marking the big 4-0 over the weekend. Hosted by Vanessa, 33, (who shares the same birthday as Lachey of Nov. 9) the party took place at the AT&T Center in downtown Los Angeles near the Staples Center on Saturday.

PHOTOS: Nick and Vanessa's cutest moments

"Well, the 40th birthday weekend has officially begun! Pray for me…gonna be a big one! Going out in style. Goodbye 30's, you were fun!!" the "Winner Is" host tweeted shortly before his birthday festivities.

"While they do share a birthday, Vanessa made this more about Nick since it's his 40th," a source tells Us Weekly.

PHOTOS: Nick and Vanessa's hot bodies

Indeed, the mom of son Camden (who turns 14 months today) invited all of her hubby's close friends to celebrate. Some of the famous pals in attendance included 'N Sync's Joey Fatone, Geoff Stults, Laila Ali, Matt Leinart, his brother Drew Lachey and his former 98 Degrees bandmate Justin Jeffre. Everyone invited received a bottle of whiskey beforehand with a cartoon face of Lachey on the label. "I LOVE creating unique invitations. This is my FAVORITE!" Vanessay tweeted on Nov. 6, along with a picture of her creation.

PHOTOS: Vanessa's maternity style

During the big shindig, Vanessa also called in a surprise favor for her hubby of two years! "Vanessa had Steel Panther perform as a surprise for Nick," the insider says. "After Steel Panther performed, Nick got on stage with them and sang 'Don't Stop Believing.'" Kid Capri, one of Lachey's favorite DJs, also helped to entertain the crowd in a "surprise after party" in a curtained off section on the rooftop.

As for Vanessa, the former MTV VJ seemed happy just to celebrate her birthday with Lachey and their baby boy. "Kickin off the birthday weekend with my two favorite guys!!!" she wrote on Nov. 7.

Alongside the caption, the "Wipeout" hostess shared a sweet picture of two wine glasses on a table next to a milk bottle belonging to the couple's son.


Boy bands voting: Hot or not?

Jessica Simpson quotes: Real or fake?

Nick Lachey talks about fatherhood