The Phillies are in the midst of a 30-game span (21-9 record) without consecutive losses on the road that began on June 5 at Pittsburgh.

Snake bitten by a ninth-inning grand slam from Ryan Zimmerman last night, the Phillies could be wondering if that streak will end this evening when they continue a three-game series with the Washington Nationals.

Philadelphia's 30-game streak is its longest since 2002 when the club set a franchise record for a single season with 30 games in a row without back-to-back defeats (May 28-August 8, 21-9 record).

The Phillies will try to bounce back in the middle contest of this set with Roy Oswalt scheduled to take the mound again. He was slated to start Friday night, but didn't take the mound after a two-hour, 22-minute rain delay. Instead, he and Kyle Kendrick flip-flopped spots in the rotation for this weekend.

Oswalt recently returned from a disabled list stint caused by a back issue and in his second game since the DL on Saturday, he halted a three-start losing streak by yielding three runs over seven innings of an 11-3 victory over the Nationals. It was the right-hander's first win since June 12 and manager Charlie Manuel said Oswalt started off throwing almost exclusively fastballs before working in his changeup, breaking ball and slider.

The 33-year-old improved to 5-7 with a 3.84 earned run average in 15 starts this season and will try to win consecutive outings for the first time since he began the season 2-0 on April 3-9. He has split two meetings with the Nationals this year and is 6-4 with a 3.17 ERA against the franchise lifetime. He is 3-1 in his last five starts vs. the Nats after going winless in his previous eight starts against them (0-2). He's also 0-2 in five career starts at Nationals Park.

John Lannan heads to the mound for the Nationals as he'll try to get a rare win over the Phillies. Lannan is 1-11 with a 5.84 ERA in 15 games vs. Philadelphia. That includes a loss one week ago against Oswalt. In that game, Lannan gave up four hits and seven runs, but just one earned, in three innings.

Zimmerman's slam on a 3-2 pitch off Ryan Madson capped a wild comeback last night. The Nationals scored six times in the ninth inning to record the 8-4 win.

"It's the ultimate when you're coming around third and your teammates are waiting [at home]," Zimmerman said of the game-winner. "Just for me to get an at-bat that inning...was pretty special."

John Mayberry, Chase Utley, Ryan Howard and Carlos Ruiz did the damage in a four-run third frame for the Phillies, who lost for the second time in four games but still maintained a healthy lead atop the NL East.

"It's very disappointing," a sullen Madson said. "To let the team down doesn't feel good."

The Phillies, who are 7 1/2 games ahead of second-place Atlanta, are 7-5 vs. the Nationals this year. Washington, though, has won four of the last five meetings.