While they came into Houston and enjoyed Monday's day off, the Nationals initially couldn't carry over the hot hitting that marked the 20 games the club had played in 20 days prior to the two-game sojourn to Texas.
Two LaRoche knocks later, all was well.
LaRoche lifted an eighth-inning double to erase a one-run Houston advantage, and his go-ahead RBI single in the ninth completed Washington's 4-3 comeback win Tuesday night at Minute Maid Park.
"The important thing right now is just winning ballgames, the [offensive] numbers will even out," said Jayson Werth. "We were able to pull out a tough, close one tonight."
Playing their first game outside the Eastern time zone, the Nationals were often flummoxed by Houston starter Jarred Cosart as they adjust to life without key cog Bryce Harper, who had surgery on his sprained left thumb Tuesday morning.
LaRoche drove one high up the left-center-field bullpen area in the eighth to tie the game, but was eventually stranded despite reaching second with no outs.
The lefty then ripped a base hit off Houston closer Josh Fields with one out in the ninth, driving in Denard Span with the game-deciding run by lacing a liner to right field.
"That's manufacturing, and there's going to be games like that, where we have to do that," said manager Matt Williams. "[LaRoche] really focused on driving in those one-run situations in Spring Training. He'll hit his share of homers, too. If he can consistently get the base hits for us, though, we'll be a better team."
The Nationals are now an impressive 12-1 when scoring at least four runs. It didn't seem like they would reach that mark for much of Tuesday night.
Werth pounced on an 0-2 fastball for a first-inning solo homer, but Cosart settled in and mostly set down Washington through the sixth. Only Jose Lobaton's shift-beating RBI double in the third halted Cosart's groove, giving Washington a 2-0 lead at the time.
"In the big leagues, it's a game of mistakes, and I had a curveball pop out of my hand in the first for the Werth home run," Cosart said. "And then I wanted to go away to Lobaton, and I cut it back across. That was kind of the story of their damage."
Cosart's counterpart, Gio Gonzalez, was only hit hard in one of his six innings before exiting on the hook for a loss.
The Astros corralled all three of their runs on two-out hits, including touted rookie George Springer's crucial two-run double, which swung the game in Houston's favor during the third inning.
And yet, Gonzalez was mostly sharp otherwise. He fanned a season-high nine, and Washington has now won five of Gonzalez's six outings. The lefty said any concern about lingering soreness in his shoulder from his last start faded once his arm got warm.
"Just need to get out of that cold air once in a while," Gonzalez said. "Rooftop open, put a little humidity out there, and that helps. Then it was just back-and-forth battling. Cosart did a great job. You have to respect that."
Gonzalez's defense provided some help with a couple of highlight-reel plays. Kevin Frandsen temporarily saved a couple runs with a backhanded snag of a ball off the high left-field wall to stall runners at second and third on Jason Castro's third-inning double.
Span matched Frandsen an inning later with a tumbling basket catch on the notoriously tricky Tal's Hill in Minute Maid's cavernous center field.
"It was nothing I could practice for, you just hope you judged it right," Span said. "Our defense had a good day in the outfield."
A fatigued Washington bullpen propped up Gonzalez's effort by breezing through the Astros' lineup, which came into the night with the lowest batting average in baseball. Tyler Clippard secured the win with a hitless eighth inning.
It gave the bats a little time to straighten out soon after Cosart, who scattered two runs over six innings, departed.
Despite LaRoche's late heroics, the Nationals left four men on base in the final two frames, and 10 overall. That contributed to the low offensive output, but Williams said the approach was satisfactory.
"Jayson lined out with guys on bases, and so did [Danny] Espinosa," Williams said. "They had a good approach against a really tough pitcher, and lucky for us, we were able to come across with one in the ninth. They stung the ball all night. That's all we can ask for our bats."
Rafael Soriano pitched a scoreless ninth to lock down his fifth save of the season, though not without a little drama due to a pair of two-out walks and a liner down the right-field line that was caught to end the game.
The win assured the Nationals of at least a split in Houston, with the brief two-game set wrapping up Wednesday before a rare second off-day this week.
Chris Abshire is a contributor to MLB.com.
This story was not subject to the approval of Major League Baseball or its clubs.