Getty Images for Breakthrough Prize

Christina Aguilera may have gotten slammed last week by Valerie Bertinelli (that wasn't really news though), but she certainly rebounded over the weekend when she debuted her post-baby body on the red carpet!

Christina and fiance Matthew Rutler attended the Breakthrough Prize Awards at NASA's Ames Research Center in Mountain View, California on Sunday night, and Xtina made sure all eyes were on her famous curves in this figure-hugging red Rubin Singer dress.

The 33-year-old singer welcomed her second child, daughter Summer Rain on August 16, and not only has she been hitting the gym hard, but she's also been working on new music. Xtina tweeted a pic from the recording studio last week and captioned it, "In more important news..." As you might know, this was just days after Bertinelli appeared on Watch What Happens Live and revealed that Aguilera once gave her "the cold shoulder" at a Van Halen concert.

But back to that rockin' body! What's her secret to shedding the pregnancy pounds? "Christina has hired a trainer and is really dedicated to getting thin again," a source told Us Weekly. "She lost 46 pounds from changing her diet and working with a personal chef."