PHILADELPHIA -- A four-day break didn't slow down the streaking Washington Nationals.
Strasburg (11-4) allowed seven hits and walked one, continuing his dominance over the Phillies. He's 13-2 against them, 6-0 in Philadelphia.
The second-place Nationals have won 16 of 20 and moved 1 1/2 games ahead of the struggling Phillies, who are 14-22 since leading the NL East by 3 1/2 games on May 29.
"In the past, when we had a long layoff, there was a tendency to be flat," Strasburg said. "I think this year we had guys who were in that situation and we weren't going to be lackadaisical. We played hard."
Strasburg said he threw during the All-Star break and Nationals manager Dave Martinez said players told him they stayed active.
"I'm really proud of the way they came out," Martinez said. "They had intensity and they played well."
Phillies starter Nick Pivetta (4-4) allowed three runs and six hits in five innings and actually lowered his ERA to 5.81.
"Lots of ups and downs," Pivetta said. "I need to improve moving forward."
The Nationals took a 2-0 lead in the second when Robles lined a single to right with the bases loaded.
Ryan Zimmerman's sacrifice fly in the third extended the lead to 3-0, but he was robbed of extra bases by center fielder Scott Kingery, who made an acrobatic, diving catch on the hard liner to the gap.
Bryce Harper was 2 for 4 against his former team.
"Strasburg had a Strasburg night," Harper said.
Phillies president Andy MacPhail said he doesn't consider the team "one trade away from the World Series" so he's going to be reluctant to trade top prospects.
"You're going to have to be judicious with your playing talent," he said.
The Phillies placed All-Star catcher J.T. Realmuto on the paternity list and selected catcher Rob Brantly's contract from Triple-A Lehigh Valley. Realmuto is expected to return Saturday.
Nationals: Max Scherzer won't start Sunday because of a sore back. An MRI was negative and he threw from 75 feet before the game. Scherzer is expected to pitch in the next series. ... LHP Jonny Venters was placed on the 10-day injured list (retroactive to July 8) with a left shoulder strain. RHP Kyle McGowin was recalled from Double-A Harrisburg to take his spot.
Phillies: Arrieta is scheduled to start Sunday despite a bone spur in his right elbow. Arrieta said he's going start by start. Surgery is likely after the season or sooner. .. INF/OF Sean Rodriguez was not available because of oblique tightness.
LHP Patrick Corbin (7-5, 3.34 ERA) starts for the Nationals and RHP Aaron Nola (8-2, 3.74) goes for the Phillies on Saturday. Corbin is 4-2 in seven career starts vs. Philadelphia, and Nola is 4-5 in 17 starts vs. Washington.
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