Heidi Klum arrives at the 64th Primetime Emmy Awards. Credit: Steve Granitz/WireImage

Heidi Klum put her best foot forward -- literally! -- at the Primetime Emmy Awards at the Nokia Theatre in L.A. September 23.

The Project Runway host, 39, showed off her toned, tanned legs in an Alexandre Vauthier dress that featured a thigh-high slit and plunging neckline. Klum completed her look with Charlotte Olympia heels, Lorraine Schwartz jewels and a Judith Leiber clutch.

"Everyone looks amazing!" the mother-of-four tweeted when she hit the red carpet. "Let's get this show started!"

Despite her blossoming romance with bodyguard Martin Kirsten, Klum flew solo on the red carpet. "He's a great man," she gushed earlier this month on Katie Couric's eponymous talk show. "We just got to know each other from a completely different side."

Indeed, a pal told Us Weekly Klum and Kirsten "have always been close. This summer the relationship developed into something more." Though the German supermodel's estranged husband Seal, 49, disapproves of their relationship, her children -- Leni, 8, Henry, 7, Johan, 5, and Lou, 2 -- "love" Kirsten, according to a source.