Keselowski turned a lap of 183.692 mph. Carl Edwards was second-fastest at 183.349 followed by Mark Martin, Jimmie Johnson and Joey Logano. Johnson, a three-time winner of the 600, won last week's All-Star Race with Keselowski finishing second.

Neither Keselowski nor Edwards has ever won a Cup race at Charlotte.

Rounding out the top 10 in practice were: Tony Stewart, Matt Kenseth, AJ Allmendinger, Kurt Busch and Jeff Burton.

Series points leader Greg Biffle was 15th in the final practice while Dale Earnhardt Jr. was 22nd. Pole-sitter Aric Almirola was 34th.

Brad Keselowski was fastest in Saturday's final practice for the Coca-Cola 600. (AP Photo)Danica Patrick, who will become the first female driver to run the 600 since 1976, was 24th fastest.

Jeff Gordon, meanwhile, continued his season-long struggles. Despite running 42 laps, more than any other driver, Gordon was 31st among the 43 drivers.