The American flyweight boxer Marlen Esparza is doing well at the London Olympics, having assured herself of at least a bronze medal. Her biggest challenge leading up to the Games, though, may have been summoning the willpower not to punch her co-star while filming this McDonald's spot from DDB in Chicago. Leaving aside the bigger issue of whether fast-food companies should be sponsoring the Olympics at all, the ad is pretty annoying across the board. Esparza, 23, who also models for CoverGirl, is accosted by a "trainer"—actually a chicken-sandwich-clutching McDonald's customer—who cynically wants her to do well at the Games so she (the customer) can win McDonald's prizes as part of the "Win When USA Wins Gold" promotion. "Chop chop," she tells Esparza after offering tips on her stance and ridiculing the Olympian's general level of effort. A lame joke about Ukranian boxers caps things off. If by some chance you're a fan of this character—who's been given the name Tara Wert, which is the real name of a DDB producer—check out a companion interview piece after the jump.