Yonder Alonso points skyward after his game-tying homer in the ninth inning (Denis Poroy/Getty Images)

SAN DIEGO – Wilson Ramos stuck his glove out, low and outside in the strike zone, hopeful that Rafael Soriano’s next pitch might end the game. Against the first two batters in the ninth inning, Soriano had spotted his fastball wherever Ramos asked, and he had dominated both. One more, and maybe Yonder Alonso would tap it for an out. One more, and Blake Treinen could claim the first win of his career. One more, and the Washington Nationals’ winning streak would grow, and they could all go home happy.

The last pitch of Soriano’s save never came. The Nationals would lose to the San Diego Padres, 4-3, when Cameron Maybin flared a walk-off single to right field off Craig Stammen in the 11th inning. But victory was averted when Soriano grooved a fastball to Alonso with two outs in the ninth inning, and he belted it high into the thick night air and just over the right field fence.

Soriano had entered with a 0.87 ERA. He had yielded zero runs in 22 of his 23 appearances this season. His stuff and command had rarely been better during his Nationals’ tenure. True to the nature of closing, it all unraveled in a flash.

“That’s it,” Soriano said. “I lost the game on one pitch.”

In the ninth and the 11th, Treinen’s six efficient innings had been rendered moot. Like that, Ian Desmond’s mammoth, go-ahead two-run homer in the seventh inning became a feat of strength rather than a game-winning clout. The break the Nationals received when Padres starter Andrew Cashner departed after six dominating innings evaporated. The Nationals’ fifth straight victory slipped away.

“It stinks that’s how the winning streak ended,” Stammen said.

The Padres’ 11th-inning rally began with two outs and the bases empty. Chase Headley ripped a single through the left side. Alonso walked to the plate again, with a chance to win the game.

Stammen had faced Alonso many times in both the majors and the minors, and Alonso had always drilled his sinker away — the numbers do not reflect how often Alonso lined out hard against him, Stammen said. Stammen decided if Alonso would beat him, he would have to beat him on his slider, down and in.

Stammen moved ahead of him, 1-2. He threw one slider in the dirt. The next veered inside, possibly at Alonso’s knees and over the corner, but it was ball three. “The umpire never calls that, because the catcher’s glove hits the ground,” Stammen said. He made a similar pitch with a full count, and Alonso held off again.

“I made two pitches exactly where I wanted to throw them,” Stammen said. “I made two really good ones with two strikes, and he just laid off of them. Maybe I could have thrown a fastball, and he wouldn’t have put as good of a swing on it. But everybody can be a Monday Morning Quarterback in that situation.”

Maybin took one slider for strike one. Stammen threw him another, just where he wanted, and Maybin dumped it into right field.

“All he could do was bloop it,” Stammen said.

“It was a good pitch,” Maybin said.

Headley steamed around third and headed home as Jayson Werth gathered the ball. He double-clutched before he fired home, but even a clean play would not have prevented the dog pile of Padres around Maybin near first base.

The game turned when Cashner departed. He had retired 16 consecutive batters and needed only 70 pitches over six scoreless innings, and he only seemed to be gaining strength – with his 67th pitch, he threw Denard Span a 97-mph fastball. But Cashner had come off the disabled list Saturday afternoon to make his first start since elbow soreness sidelined him May 13.

Padres Manager Bud Black had said leading up to the game that Cashner could throw roughly 90 pitches. But he pulled him after 70, leaving a 2-0 lead in the hands of right-handed reliever Nick Vincent.

“The way he was throwing the ball, he was hitting his spots, he is one hell of a pitcher,” Kevin Frandsen said. “Anytime you could get him out of the game, it’s a big thing.”

In a blink, no longer reckoning with Cashner’s high-90s seeds, the Nationals struck. Adam LaRoche and Ryan Zimmerman blooped doubles to score the Nationals’ first run. With two outs, Desmond walked to the plate with Zimmerman still on second.

Vincent fired Desmond three consecutive sliders. He took the first for a ball. He fouled off the second. And he destroyed the third.

Thick, marine air rolls over Petco Park at night, around the third inning most games, and forms an invisible wall above center field. Hitters curse it. Pitchers love it. Baseballs die when they run into it. Home runs in the latter innings rarely occur, and when a ball manages to clear the fence in right-center field, it tends to creep over.

For the past two nights, the cool night air had knocked down doubles and homers. Desmond’s blast seared through it. It landed in a bush just to the right of dead-center, 432 feet away from home plate. As he rounded first, Desmond patted his helmet with his left hand.

At night at Petco Park, “I’ve only seen a couples balls hit that far,” Frandsen said. “And they were by Bonds.”

Rid of Cashner, the Nationals had taken the lead. Now, for Treinen to secure his first win in his third career start, they needed to keep it. Jerry Blevins and Drew Storen teamed for a scoreless seventh.

Clippard entered the eighth with 18 consecutive scoreless appearances, and he needed a patented escape to reach 19. Rene Rivera led off with a double to left and moved to third on Chris Denorfia’s sacrifice bunt.  Clippard recorded a key out when Everth Cabrera flared to shallow center and Span chased it down.

With two outs, pinch hitter Carlos Quentin lumbered to the plate. Once the count reached 1-2, Clippard fired his trademark change-up. Quentin swung like a blindfolded toddler trying to hit a piñata. Strike three.

The ninth belonged to Soriano, who would face the Padres’ 3-4-5 hitters. Soriano blew away Seth Smith in four pitches. Headley hit a dribbler back to the mound. Soriano dotted his two-seam fastball, and he needed just one more out.

He fell behind Alonso with a first-pitch ball. Ramos called for a fastball and set his target at Alonso’s knee, on the outside corner. Soriano’s pitch sailed letter-high over the middle of the plate. Alonso launched into the sky. Werth backpedaled until he reached the right field fence, stationing himself on the warning track, where all he could do was watch the ball drop on the other side. The game had been tied, and it headed into extra innings.

“That’s what happens,” Soriano said. “It only has to be one pitch.”

For most of the night, Treinen induced weak contact and cruised through the Padres’ weak lineup. He needed only 63 pitches for his six innings, and he recorded 12 of his 18 outs with groundballs. He did not walk anyone, which means in the last full turn through the Nationals’ rotation, their starters struck out 32 and walked one in 36 innings.

In the early innings, Treinen steamrolled the Padres with his mid-90s sinker. He threw almost nothing else, and the Padres kept rolling it to infielders. Treinen only threw 12 of his first 23 pitches for strikes, but the Padres produced a fusillade of groundballs – seven of the first nine hitters Treinen faced hit the ball on the ground.

The second time the middle of the Padres’ lineup faced him, though, hitters began to see his sinker better, and his imprecision hurt him. With one out in the fourth inning, Headley smashed a belt-high, 95-mph sinker to left-center field to score the game’s first run. Two batters later, Maybin smoked a liner into the left field corner and gave San Diego a 2-0 lead.

Treinen would not rattle. He retired the next six hitters he faced, and the Nationals entered the seventh still down two runs, still within striking distance.

The Nationals squandered their only chance off Cashner with faulty base running. With one out in the first inning, Kevin Frandsen singled to right field. Werth followed with a double off the base of the right field fence, and the Nationals had put two men in scoring position with one out for cleanup hitter LaRoche.

As LaRoche took ball one, Frandsen crept down the third base line. Padres catcher Rene Rivera noticed him advancing too far. The Padres called a play — Rivera would fire to third on the next pitch. When Cashner threw a 1-0 change-up outside, and Frandsen again danced down the line, Rivera popped up as soon as he received the pitch and fired to third. Frandsen scampered back and dove, but the throw beat him easily.

With little to gain, Frandsen had run the Nationals’ out of an ideal early scoring chance. LaRoche walked, but as Frandsen fumed at himself in the dugout, Zimmerman’s groundout to shortstop ended the inning.

“We had the momentum right there,” Frandsen said. “It obviously kills it. It something that should never happen, but it happened.”

In the end, the play may made the difference. But the Nationals could find solace in the company of their division rivals. They remained one game out of first as all five National League East teams lost and three blew one-run, ninth-inning leads. In Arizona, the Atlanta Braves blew one in the ninth and the 10th. The Nationals were not alone in knowing how much one pitch can mean.