The Oscar winner was one the many celebs at the Toth-hosted Art Mère/Art Père art auction benefit for Livestrong.
But it almost turned into a loveless evening for Ms. Witherspoon...
Don't worry, all is good on the home front. Witherspoon got into a bidding war for a photo of signage from the Loveless Motel, a famed landmark in her native Nashville.
While she lost on that item, she did go pick up a painting of multiple American flags by artist Jeff Cahill for $1,600.
Also at the event were Matthew McConaughey and Camila Alves, enjoying the Fatburger truck and drinks from Corzo tequila; Johnny Galecki, checking out the bright yellow Ferrari Italia 458 on display next to the red carpet; and Sanaa Lathan, hitting the JetBlue kiosk.
Eli Roth was there. The Inglourious Basterds star's artist mom, Cora Roth, donated a mixed media work called Pink Light to the auction. "I'm her plus-one tonight," Eli smiled.
In other star sightings...
E!'s own Giuliana Rancic hosted last night's UCLA Department of Neurosurgery's Visionary Ball.
Mommy-to-be Hilary Duff relaxed with a mani-pedi at the Nail Garden in Burbank.
Coming Up: Prime Suspect star Maria Bello, Joy Bryant, Julie Bowen, Kristin Davis and Lisa Kudrow are among those teaming up with celebrity jeweler David Yurman for the 20th anniversary of P.S. Arts event on Tuesday at the Sunset Tower Hotel.
Attention readers! Run into any celebs recently? Tell us all about it at MarcMalkin@comcastnets.com.