In his last eight starts, Jordan Zimmermann has a 2.26 ERA. And in his last 21 innings, he’s allowed two earned runs. (Lenny Ignelzi/Associated Press)

Saturday night, after another impotent performance by the Washington Nationals’ offense, Jayson Werth stood in front of his locker and diagnosed the gulf between the team’s hitting and the rest of the operation. Could they keep relying on pitching and defense only? No, he declared. “You gotta hit to win,” Werth said. “Hitting is definitely not a bonus.”

The Nationals again tested the limits of that self-evident truth Sunday afternoon, during a 2-0 victory over the San Diego Padres at Petco Park packed with milestones, missed chances and spectacular pitching. Jordan Zimmermann struck out 10 batters in seven scoreless innings, allowing just four hits — all singles — while walking one. The Nationals’ defense did not commit an error for the 11th consecutive game, which set a franchise record.

And the Nationals finished their 11-game Western road swing with three straight victories in which they scored two runs, giving them a 6-5 record on the trip. The Nationals had not concluded a multi-city road trip with a winning record since May 2008.

“It’s very significant,” second baseman Danny Espinosa said. “I think this could really put us on a roll.”

On Tuesday, the Nationals plan on taking Ryan Zimmerman off the disabled list and sliding him back into their lineup, “a huge boost,” Zimmermann said. Their starting pitchers are giving the Nationals reason to think they can win any day. In seven of their past eight games, the Nationals’ starter has allowed one or zero earned runs. “I’ve never had a club that has done that,” Manager Jim Riggleman said.

All of those good feelings would have been dashed if the Nationals had finally not converted a scoring chance in the ninth inning, when Espinosa drove in the game-winning run with a near-grand-slam sacrifice fly.

For eight innings, the Nationals’ hitters took brilliant starting pitching and flawless defense, rolled them up and tossed them in a wastebasket. Entering the ninth inning, the Nationals had gone 0 for 12 with runners in scoring position. And then Matt Stairs, who walked to the plate 4 for 39, started another rally with a one-out, pinch-hit single to center field.

“I actually hit a curveball today,” Stairs said. “That’s probably the first time I hit a curveball in six or seven years for a base hit.”

Alex Cora, who batted ninth behind Zimmermann, followed with a single, his third hit of the day. Up came Werth, who twice had come to the plate with two runners in scoring position and one out, and had twice made a rally-crippling out — one strikeout and one liner smashed straight at the shortstop. He took three balls from closer Heath Bell, then two strikes. He fouled off a pitch. He laid off a slider just off the outside corner. Ball four, bases loaded.

Up came Espinosa. He crushed a flyball toward the wall in right field and thought, maybe, he had hit a grand slam. Chris Denorfia drifted back and made an astounding, leaping catch, his body crashing into the fence.

Pinch runner Brian Bixler scampered home easily, and Cora went to third after getting caught in a rundown by avoiding the tag. (“He missed the call,” Cora admitted. “He tagged me. We got a break.”) When Laynce Nix followed with a line-drive single, Cora scored to make it 2-0 before Werth was thrown out at the plate.

The furious rally saved an indelible pitching performance from irrelevance. Zimmermann used only sliders and fastballs the first time through the Padres’ order before breaking out his curve. Zimmermann pumped low strikes and at key moments rifled chest-high fastballs — “moving eye levels,” he said.

After Zimmermann put two runners on with one out in the fourth, he retired the final 11 batters he faced. He felt stronger and more in control of his fastball than he had all game. Zimmermann’s masterpiece both added to and improved upon his remarkable recent stretch. In his past eight starts, Zimmermann has a 2.26 ERA.

And in his past 21 innings, he’s allowed two earned runs. If he is not regarded as one of the best starters in baseball, “he deserves to be,” Werth said.

In the two phases of the game that do not require a hunk of wood, the Nationals have played as well as possible. The Nationals did not make an error during their road trip, setting a franchise record for most consecutive games and innings (1042 / 3) without an error. In the past 13 games, Nationals starting pitchers have a collective 2.25 ERA. Sunday, after Todd Coffey rolled through the eighth, Drew Storen saved his third straight game, giving him 15 on the season in 16 tries.

“There’s only one thing we need to do more of,” Werth said. “We need to hit. But if we’re going to win ballgames 2-0, that’s what we’re going to do.”

Sunday afternoon, the Nationals celebrated in their dugout and then lined up to shake hands. The next time they took field, they knew, their best player would be alongside them. They had won, and they were going home.

After the Nationals packed and most of them had already walked out of the clubhouse, someone told Werth to have a nice flight home. “You don’t have to worry about us,” he replied. “It’s going to be a good flight.”