JOLIET, Ill. — Matt Kenseth restored order to a chaotic week for NASCAR with a steely victory over teammate Kyle Busch in the opening race for the Chase for the Sprint Cup championship. The top seed at the start of the Chase, Kenseth slid into Chicagoland Speedway under the radar as all the attention centered squarely on NASCAR's investigation into the manipulation attempts of at least three teams to alter the outcome at Richmond the previous week. It led to severe sanctions against Michael Waltrip Racing, Martin Truex Jr. was replaced by Ryan Newman in the Chase field, and after NASCAR continued to review incidents long after cars began to practice for Sunday's race, NASCAR chairman Brian France took the unprecedented step of expanding the field to 13 drivers to add Jeff Gordon.