Christina Aguilera performed at the Breakthrough Prize Awards Sunday, making it her first appearance since giving birth to her second child.

The awards show, hosted by Seth MacFarlane, honored 14 scientists who are changing the world. On Saturday, the Breakthrough Prize Awards will be broadcasted on the Discovery Channel and the Science Channel on Saturday.

She turned heads with her blonde flowing curls while she sung a rendition of her song "Beautiful" to a group of scientists.

The 33-year-old wore a long-sleeved, floor-length red Rubin Singer dress and Christian Louboutin pumps. Her lips were a bold shade of red to match her beautiful dress.

Christina gave birth to her daughter Summer Rain Rutler, on Aug. 16. Her first child, conceived with ex-husband Jordan Bratman, is 6-year-old Max.

"She's definitely more confident the second time around with motherhood," an Aguilera insider told People Magazine.

"What a Girl Wants" singer is shooting the eighth season of "The Voice" and working on a new album.

The singer's fiancé Matthew Rutler accompanied her on the red carpet for the night. They've been going strong since first meeting on the set of her 2010 film "Burlesque."

On Valentine's Day, Rutler popped the question a week before news about their new baby girl was out.

The Production Assistant, Rutler, was a good friend during her divorce with Bratman. The two were seen together on the red carpet a month after she filed for divorce.

After Aguilera sold her Beverly Hills mansion she shared with Bratman for $11.5 million, she moved into a $10 million Mulholland Estates mansion in Los Angeles with Rutler and Max.

Prior to the event, the songtress tweeted a photo of her back in the studio. Throughout the pregnancy, she tweeted about being hard a work making new music.

"Baby girl getting first listen to what mama's been creating in the studio," she tweeted Aug. 11.