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The National League East-champion Washington Nationals can still capture homefield advantage with the best record in the Senior Circuit and will shoot for a series win over the Philadelphia Phillies this afternoon.

The Nationals and Cincinnati Reds share identical 97-64 records, but Washington can clinch home-field advantage throughout the playoffs with a win Wednesday or a loss by the Reds. Washington owns the tiebreaker with the Reds.

Washington moved closer to that achievement with Tuesday's 4-2 win over the Phillies, as Adam LaRoche homered and Steve Lombardozzi knocked in a pair of runs. The home run gave LaRoche 100 RBI on the year, making him the third player to record that many in a season for the Nationals (Ryan Zimmerman, Adam Dunn).

"It's kind of a milestone to reach 100," LaRoche said. "If I would have finished on 99, it would have been a tough pill to swallow looking back at how many opportunities I have had."

Zach Duke picked up the win with a scoreless inning of relief and Drew Storen closed the door in the ninth for his fourth save. Tom Gorzelanny got the start over staff ace Gio Gonzalez and allowed one run in 3 2/3 innings for the Nationals, who entered the night having lost three of four games.

Edwin Jackson looks to break out of his funk before the postseason when he takes the mound today. Jackson is 0-2 in his last four starts -- all Washington losses -- and 2-4 in his past six decisions. In a 12-2 pounding at the hands of St. Louis at Busch Stadium on Friday, Jackson was banged around for nine runs, eight of which were earned, and six hits in 1 1/3 innings.

Jackson is 9-11 with a 4.13 earned run average in 30 starts this season and lost to Philadelphia back on Aug. 24. In four career starts against the Phillies, the right-handed Jackson is 0-4 with a 5.32 ERA.

Philadelphia has lost four of seven games and hopes to finish with a record above .500 for a 10th consecutive season (81-80).

Out of the playoffs for the first time since 2006, the Phillies had a three- game winning streak stopped with Tuesday's defeat at Nationals Park. Youngster Darin Ruf hit a pair of solo homers and B.J. Rosenberg did not factor in the outcome of his first career start, touched for one run in four innings.

"Coming into the final stretch here knowing that I was going to get to play a little bit, I was just trying to put myself in a spot where I can compete next year in spring training for, if not a starting job, then a spot on the team," Ruf said.

Josh Lindblom allowed two runs on three hits in the sixth to take the loss.

Phillies shortstop Jimmy Rollins is most likely finished for the year due to a calf injury. Rollins, who signed a three-year, $33 million deal in the offseason to stay in Philly, ended the campaign hitting .250 with 33 doubles, five triples, 23 home runs, 68 RBI, 102 runs and 30 stolen bases.

Cliff Lee will put the finishing touches on what has been a frustrating year for the southpaw. Lee gets the nod today and is only 6-8 with a 3.12 earned run average in 29 starts. He is 0-1 in his past two starts since going 4-0 in his previous five -- all Philadelphia victories -- and did not record a decision in Friday's 2-1 loss at Miami. He gave up one run in seven innings.

Lee has allowed just three runs over his past four outings and defeated Washington back on Aug. 26 with seven innings of one-run ball in a 4-1 triumph. He is 5-2 with a 2.28 ERA in seven career meetings with the Nats.

The Phillies are 9-8 against the Nationals this season.