Jayne Kamin-Oncea/US PresswireClayton Kershaw is set to finish his season with starts tonight and then Sunday in San Diego.How heated is the National League Cy Young competition? The top four candidates — Roy Halladay, Ian Kennedy, Clayton Kershaw and Cliff Lee (in alphabetical order) — have a combined September ERA of 1.46.Kennedy continued his late bid for recognition by pitching eight innings of one-hit ball with 12 strikeouts in a 1-0 victory for Arizona, which built its lead to 5 1/2 games in the NL West, while Halladay gave up a sliver of ground by allowing four runs in a 4-3 Phillies loss to St. Louis.Kershaw and Lee — both red-hot of late, both scheduled to start tonight — have the opportunity to affirm themselves as the two top finalists for the award. In p