Roy Halladay and Jayson Werth made certain that the Philadelphia Phillies claimed their fourth consecutive NL East title.

Halladay notched his major league-leading 21st victory after tossing a two-hit, complete-game gem and Werth belted a solo homer and drove in four runs as the Phillies cruised to an 8-0 triumph over the Washington Nationals on Monday.

Chase Utley and Carlos Ruiz had run-scoring doubles and Placido Polanco added an RBI single as Philadelphia (94-63) improved to 18-3 in road games since Aug. 1.

Halladay (21-10) posted his fifth straight win and improved to 8-1 in 12 career appearances against the Nationals' franchise. The 33-year-old struck out six for his ninth complete game of the season and 58th career.

Wilson Ramos and Adam Dunn singled for the Nationals (67-90), which lost for just the second time in seven games.

John Lannan (8-8) didn't celebrate his 26th birthday in grand fashion on Monday. The southpaw fell to 0-8 in 11 career starts against the Phillies after permitting four runs and seven hits in 5 2/3 innings.