LOS ANGELES — The Dodgers clinched their first NL West championship in four years Thursday without lifting a bat.

The Dodgers entered the day with a magic number of one, and got what they needed when the second-place Arizona Diamondbacks lost 12-3 at St. Louis in the afternoon. That was several hours before Los Angeles faced the San Diego Padres in the Dodgers' final home game of the regular season.

Los Angeles has won just one postseason game since winning the World Series 20 years ago, going 1-12 in four playoff appearances.

The Dodgers were in deep trouble after losing their eighth straight game Aug. 29, a 9-3 setback at Arizona that gave the Diamondbacks a 4›-game lead in the division. But with Manny Ramirez leading the way, they entered Thursday night's game having won 18 of their prior 23 games.