Washington’s Jeter Downs slides across home plate to score on a double by Joey Meneses to take the lead in the fifth inning against the Red Sox on Wednesday in Washington. Andrew Harnik/Associated Press

WASHINGTON — The Red Sox didn’t do much at the trade deadline, but they had reasonable expectations that getting Chris Sale and Trevor Story back from injuries would bring some energy to their postseason push.

It didn’t work out that way during a series at Washington.

Sale couldn’t make it through the fifth inning in his second start back from a shoulder injury, and Boston suffered another blow to its playoff hopes, losing 10-7 on Thursday and dropping two of three to the last-place Nationals.

The Red Sox fell to 7-8 in August and slipped 3 1/2 games behind AL East rival Toronto for the final wild-card spot. Story, who had offseason shoulder surgery and made his season debut on Aug. 8, went 0 for 5 and was hitless in the three-game series.

“It’s literally on to the next,” Story said. “I think if we play the way that we want to play and the way we can, then we’ll be where we want to be when the postseason comes.”

Luis Urías hit a grand slam in the seventh inning as Boston tried to rally from eight runs down. It was the first career grand slam for Urías, a backup infielder who was acquired from Seattle at the deadline. Two batters later, Rafael Devers added a 453-foot, two-run homer to get the Red Sox within 9-7.

“That’s what these guys do. They can hit the ball. When they get something going, they can score on you really quick,” Nationals Manager Dave Martinez said. “The good thing is, we scored more today.”

Trailing 10-7 entering the ninth, Boston made one last push against Kyle Finnegan. Connor Wong led off with a single and pinch-hitter Jarren Duran broke out of a 2-for-27 slump with a double. But Finnegan retired the next three batters to secure his 19th save in 26 chances.

“To beat those guys two out of three games, it’s pretty awesome,” Martinez said.

Sale (5-3) was expected to throw about 75 pitches but was lifted with one out in the fifth after he walked Alex Call and Jeter Downs and retired Lane Thomas on a flyball with his 65th offering.

Sale’s first two pitches to No. 9 hitter Downs, who was trying to bunt, appeared to catch the top of the strike zone but were called balls by plate umpire Mark Wegner.

“I’m not going to get into that. I’ll let you guys be the judge of that,” Sale said to reporters.

Josh Winckowski came in and gave up a tiebreaking two-run double to Joey Meneses, the first of four straight hits by the Nationals, who scored five times in the inning.

“Super frustrating. I’m not even really too upset about the runs I gave. More upset about his, for sure,” Winckowski said.

The Red Sox are fourth in the AL East, ahead of only the imploding Yankees. Boston heads to New York for a three-game series against its rival starting Friday.

“As long as we got a chance, I like where we’re at,” Sale said. “Even today, it showed. … We kept fighting back.”

Meneses drove in five runs and Patrick Corbin (8-11) pitched six sharp innings for the rebuilding Nationals, who have won 14 of 17 at home and improved to 21-13 since July 8.

Keibert Ruiz went 3 for 3 for Washington, extending his hitting streak to seven games. He is 13 for 28 over that span. Stone Garrett drove in three runs.

Rookie Triston Casas hit his 20th homer of the season for the Red Sox in the third. That was Boston’s only run against Corbin, who gave up four hits, struck out six and walked none.

“I thought we did a good job mixing up fastball inside and out, getting ahead,” Corbin said. “Pleased overall. It was great to see the offense put up those runs, and we were able to hold on.”

Sale was charged with three runs, two earned. He gave up two hits, walked three and struck out three.

NOTES: Red Sox Manager Alex Cora said the team was providing support for Duran, who indicated on social media that he was struggling mentally. He was out of the lineup Wednesday and Thursday against left-handed starters. He will be in the lineup this weekend against the Yankees, Cora said. … Justin Turner, limited to DH duty because of a bone bruise in his left heel, got the day off.