January Jones is wowing fans in new western Sweetwater by baring her breasts for one gritty scene.

The Mad Men star plays a gun-toting, red-headed prostitute, who sets out to seek vengeance on the men who killed her husband.

In one scene, she faces down a villain while bathing in a stream - and has to tackle him wearing just her 1800s under garments.

The acclaimed new movie also features Jason Issacs and Ed Harris.