(SportsNetwork.com) - The Washington Nationals can still pick up their eighth consecutive series victory when they close out a three-game set versus the Philadelphia Phillies Sunday afternoon.

The Nationals won Friday's opener 2-1, but dropped the middle test by an 8-1 score. Stephen Strasburg did not have his best stuff and lasted only 3 2/3 innings, charged with six runs (5 earned) and seven hits.

"It's definitely something I've never experience before," Strasburg said of his struggles. "I think it's a test for me and I'm going to look at it that way. I'm not going to quit, I'm going to keep going and battle through this."

Ian Desmond drove in Washington's lone run and Bryce Harper was 0-for-4 with a pair of strikeouts.

Washington had its six-game winning streak stopped and the NL East leaders are still 12-3 in the past 15 games. The club will start a six-game road trip Monday against the Chicago Cubs and Cincinnati Reds.

The Nationals have won each of Gio Gonzalez's last four starts and the left- hander takes the mound Sunday. Gonzalez has recorded back-to-back no-decisions and hasn't pitched well in either outing, allowing a total of 11 runs and 15 hits across 10 innings. In Tuesday's 8-6 win over the New York Yankees, Gonzalez was touched for six runs and six hits in five innings.

He gave up five runs and nine hits in five innings of a 9-6 win at Arizona on May 13. Gonzalez is 3-2 with a 4.94 earned run average in eight starts this season and the Nationals have scored 26 runs in his past three appearances.

The southpaw lost at Philadelphia on April 10 and gave up three runs in 6 1/3 innings of a 4-1 setback and is 6-5 with a 3.15 ERA in 13 career starts in this series.

Philadelphia was able to halt a two-game slide and win for the eighth time in the last 11 tries on Saturday. Ryan Howard was 3-for-5 with a home run, two RBI and two runs scored, while Maikel Franco went deep for the Phils. Ben Revere chipped in two hits, an RBI and scored three times.

"Against a guy like Strasburg you have to keep making adjustments," said Howard. "He left me a couple of pitches up and I was able to make some good swings on them."

Cole Hamels improved his pending trade value with eight innings of one-run ball, struck out five and walked one batter. Justin De Fratus gave Hamels a breather with a scoreless ninth inning.

The Phillies are 3-3 on a 10-game road trip and will visit the New York Mets next for three games at Citi Field.

Aaron Harang's first season with the Phillies has been a productive one and he gets the nod Sunday. Harang is 4-3 with a solid 1.82 earned run average in nine starts and did not figure into the decision of a 6-5 loss at Colorado on Tuesday, as he permitted three unearned runs and three hits in six innings.

Harang, who threw eight shutout innings in a 4-2 win over Pittsburgh on May 14, has pitched at least six innings in every start this season. The veteran right-hander defeated Washington on the road April 18 in a 5-3 verdict and was reached for three runs in six innings.

In 14 career starts against the Nationals, Harang is 4-5 with a 3.16 ERA.

The Nationals are 5-4 against the Phillies this season.