WASHINGTON -- A Washington homestand that began with three losses to Atlanta was about to culminate in a six-game winning streak and the Nationals at .500 for the first time since mid-July.
One swing of the bat rewrote that happy ending.
Pinch-hitter Hector Sanchez hit a three-run homer with two outs in the ninth inning and the San Francisco Giants beat the Nationals 4-3.
Down to his last strike, Sanchez connected off closer Rafael Soriano (2-3) on a 3-2 pitch. The drive landed just inside the right field foul pole in the second deck.
"That one hurt. That one hurt," Washington manager Davey Johnson said.
The loss kept the Nationals (59-61) from reaching .500 for the first time since July 20.
Ian Desmond doubled home two runs and Jayson Werth added two hits for the Nationals.
Buster Posey led off the ninth with a single against Soriano and Roger Kieschnick drew a two-out walk. That set the stage for Sanchez, who was pinch hitting for Javier Lopez.
Soriano, pitching for the third straight day, got ahead in the count 0-2, but Sanchez worked the count to 3-2 on a pitch that umpire Jim Joyce ruled high, but that Soriano felt was a strike. Sanchez homered on the next offering.
"I try to throw (a) cutter in. I think it was a bad pitch," Soriano said of the home run pitch. "At the same time, I think the game (should have been over). That (2-2) pitch, to me, I think it (was) a strike. I think that's when the game changed."
Johnson pointed to the walk to Kieschnick.
"Basically (Joyce) called the low strike all day and didn't call the high strike. He was consistent with that," Johnson said. "He gave a lot of borderline pitches low. It wasn't that pitch. Walking the left fielder and he had Posey two strikes and threw a hanger. But walking the left fielder."
Lopez (2-2) pitched 1 2-3 scoreless innings of relief to earn the win. Sergio Romo worked a scoreless bottom half for his 29th save.
The loss spoiled Dan Haren's six-inning, one-run effort. Since coming off the 15-day disabled list on July 8, Haren has a 3.20 ERA in seven starts.
"Dan did a great job. He's been great," said Desmond, who reflected on the winning streak. "A lot more positives than negatives, but right now I think we're just kind of resting on the negative. Shake that off and we'll be ready to go tomorrow."
Brandon Belt homered for the Giants and extended his hitting streak to 10 games. Ryan Vogelsong allowed three runs in the third inning, all with two outs. San Francisco snapped a three-game losing streak.
"It doesn't get any bigger than that. You're down to your last strike and he hit it," manager Bruce Bochy said one day after a Giants ninth-inning rally fell short in 6-5 loss.
"But the boys needed this. To come up short last night after fighting so hard there in the ninth. Save a little sanity here."
Vogelsong laboured during a 39-pitch third inning. Desmond's double into the gap in left-centre drove home both Denard Span and Werth.
Adam LaRoche then followed with an RBI single to score Desmond and put the Nationals up 3-0.
In the seventh inning, LaRoche's line drive struck Giants reliever Sandy Rosario in the chest. Rosario immediately left the game and was replaced by Lopez. Bochy said Rosario has a bruised sternum and is day-to-day.
San Francisco's struggling offence did little against Haren, who during one stretch allowed just two runners to reach base out of 14 batters. One of those runners came via error and was erased by a double play.
Belt snapped that stretch with a home run in the sixth inning to cut the deficit to 3-1. But Haren escaped the inning without further damage. He threw 98 pitches and gave up three hits with two walks and three strikeouts.
NOTES: Washington agreed to terms Thursday with international free agent 3B Anderson Franco, 16, of the Dominican Republic. . The Nationals recalled RHP Drew Storen from Triple-A Syracuse and optioned RHP Ryan Mattheus to Syracuse. ... Nationals C Wilson Ramos (strained hamstring) missed his second straight game. Washington manager Davey Johnson said Ramos will return to the lineup Friday in Atlanta. . The Nats begin a three-game series with the NL East-leading Braves. RHP Taylor Jordan (1-3, 4.14) opposes LHP Alex Wood (2-2, 2.78).