Nice job, K-Cavs!

Although Kristin Cavallari has been snapped out and about since giving birth to son Camden nearly two months ago, Wednesday Oct. 2 marked The Hills star's first post-baby red carpet.

PHOTOS: Kristin Cavallari's bump style

And the 25-year-old did not disappoint! Hosting the ULTA Beauty "Donate With a Kiss" event at the James Hotel in downtown NYC, Cavallari flaunted her svelte post-baby body in a sexy cocktail dress and stiletto heels; engaged to Camden's dad, Jay Cutler, the new mom beamed for photographers and worked a fresh-faced makeup look, her blonde looks in loose, waves.

PHOTOS: Her bikini body

The Big Apple bash helped promote Ulta Beauty's new campaign to benefit Breast Cancer Research. (Learn more about giving at

Famous for her bikini bod, Cavallari has been working hard to lose the baby weight. "Walking uphill on the treadmill to work out this booty," she tweeted Sept. 13. "Bye bye baby weight."

PHOTOS: The Hills stars then and now

Indeed, a source told Us Weekly, the former reality star has been "working out like crazy with a trainer."

She and Chicago Bears quarterback Cutler, 29, got engaged in November 2011 after a brief split; no word yet on their wedding date.

This article originally appeared on Wow! Kristin Cavallari Debuts Skinny Post-Baby Bod on Red Carpet