Division titles on the line in regular-season finale

(Reuters) - Four divisional titles are still up for grabs as well as a four-team race for a wild-card playoff spot heading into Sunday's regular-season finale in the National Football League. Showcase games will decide three National Football Conference (NFC) titles and one in the American Football Conference (AFC). The winner of the Detroit Lions at Green Bay Packers game will secure the NFC North title with NFC South honors going to the winner of the Carolina Panthers at Atlanta Falcons game. Arizona can clinch the NFC West with a win at the San Francisco 49ers and a loss by the Seattle Seahawks, who are at home to the St. Louis Rams. Seattle will claim the title if they beat St. Louis. In the American Football Conference, the only division title not yet clinched is the AFC North where either the Cincinnati Bengals or the Pittsburgh Steelers would claim honors by winning their mouthwatering showdown at Pittsburgh. The San Diego Chargers, Baltimore Ravens, Houston Texans and Kansas City Chiefs also have an opportunity to advance into the postseason. The Chargers, led by five-time Pro Bowl quarterback Philip Rivers, face perhaps the likeliest path into the playoffs with a road game against Kansas City, who will be without their signal-caller Alex Smith, due to a lacerated spleen. San Diego (9-6) would seal a wild-card playoff berth with a victory over Kansas City (8-7) while the Chiefs' own slim post-season hopes depend on a home win and other results going their way. Baltimore and Houston would need wins and at least a loss by San Diego to be in the running. (Reporting by Mark Lamport-Stokes in Los Angeles; Editing by Gene Cherry)