Raul Ibanez had a two-run single to highlight a six-run first inning and Roy Oswalt tossed six strong frames as the Philadelphia Phillies cruised to a 9-1 triumph over the Washington Nationals on Friday.

Jayson Werth and Carlos Ruiz homered and drove in two runs apiece and Wilson Valdez and Oswalt added RBI singles as Philadelphia (87-61) won its fifth straight and improved to 12-3 in September.

The NL East-leading Phillies remained three games ahead of the Atlanta Braves (84-64), who recorded a 6-4 victory over the New York Mets on Friday.

Acquired from the Houston Astros for left-hander J.A. Happ and a pair of prospects, Oswalt (13-13) has posted a 7-0 mark since Aug. 11. The 33-year-old right-hander allowed one run and six hits while striking out seven in six innings to pick up the win.

Chad Durbin, Jose Contreras and J.C. Romero worked one scoreless inning apiece to secure the victory.

Ryan Zimmerman went 4-for-4 with an RBI single in a losing effort for Washington (62-85).

Jason Marquis (2-9) never got out of the blocks in this one. The 32-year-old right-hander permitted six runs and six hits in just one-third of an inning to take the loss.