SAN DIEGO (AP) -- Although they're struggling for runs, the Washington Nationals found a way to score when they needed it most.
The Nationals used Danny Espinosa 's go-ahead sacrifice fly in the ninth inning for a 2-0 win over the San Diego Padres on Sunday.
Washington won its third straight game against the Padres to win the four-game series after taking consecutive 2-1 victories.
"It felt good to finally get one in," Espinosa said. "It feels even better to win the road trip."
Espinosa got robbed of an extra-base hit when right fielder Chris Denorfia made a leaping catch against the short right-field porch. But pinch-runner Brian Bixler scored anyway.
"I wasn't sure because the field plays so big," Espinosa said. "I thought it might have a chance, but he made a great play. I was just trying to drive the ball. I didn't want to hit in on the ground where it's a double play."
Espinosa was robbed of a solo homer when Will Venable scaled the center field fence to pull in a long fly ball in the Nationals' 7-3 loss Thursday to San Diego.
Washington, which finished 6-5 on its longest road trip of the season, was hitless in 12 at-bats with runners in scoring position heading into the ninth inning. The Nationals were 13 for 91 with runners in scoring position on the trip.
"It was very rewarding, a good feeling to come through in the ninth," Washington manager Jim Riggleman said. "Earlier in the year when we weren't driving them in, I felt like I'd rather have them on than not having them on."
The Nationals won the franchise's first series in San Diego since 2001. It was also Washington's first three-game road winning streak since April 2010.
With one out, the Nationals got a pinch-hit single from Matt Stairs off Heath Bell (2-3). Bixler replaced him at first and went to second on Alex Cora 's single. Jayson Werth drew a full-count walk before Espinosa's sacrifice fly.
Laynce Nix followed with an RBI single to right, but Werth was thrown out trying to score by Denorfia.
"I didn't do my job," Padres closer Heath Bell said. "If I had done my job we would have won this game."
Bell was also the loser in Wednesday's 5-3 loss to Colorado when he allowed two ninth-inning runs.
Stairs, who played last season for San Diego, was surprised with his key hit to start the inning.
"That's the first time I hit a curveball in about six or seven years," he said.
Todd Coffey (2-0) pitched one inning and Drew Storen pitched the ninth for his 15th save in 16 changes to combine with Jordan Zimmermann on a five-hitter.
It was 11th time the Padres have been shut out this season, tops in the majors.
Two of the NL's worst offensive teams combined to score eight runs in the final three games of the four-game set.
Zimmermann struck out 10 and gave up four hits over seven innings. He has allowed just two runs over 21 innings of his last three starts.
San Diego's Tim Stauffer allowed five hits in seven innings with four strikeouts, three walks and hit two batters. The right-hander was coming off a career-high eight-inning effort where he struck out a career-best eight batters in a 2-0 win over Colorado on Tuesday.
The Nationals loaded the bases with one out in the first inning but Stauffer got Wilson Ramos to bounce into a double play.
In the seventh, Washington had runners on second and third with one out. Stauffer got Werth to hit a line drive right at shortstop Jason Bartlett , then struck out Espinosa.
San Diego's biggest threat was in the second when they had bases loaded with one out on a walk and two singles. Zimmermann escaped damage with consecutive strikeouts against Alberto Gonzalez and Stauffer.
The Padres, 14-26 at home, finished their season-longest 11-game homestand with a 5-6 record.
NOTES: The Nationals set a franchise record in the third inning by reaching 97 2-3 innings without an error. That broke the mark set by the Montreal Expos in August 1977. ... Werth was in the leadoff spot with the pitcher hitting in the No. 8 slot for the second straight game. ... Stauffer threw a career-high 111 pitches.