Zimmerman's double came against Houston starter Scott Feldman, who surrendered three runs, five hits, struck out three and walked one in 3 2/3 innings.
Nationals left-hander Gio Gonzalez, starting four days after the birth of his first son, was erratic in the early going before settling down to throw 4 1/3 innings of one-run ball. He also allowed five hits, walked four and struck out one.
"He threw the ball really well," Ramos said of Gonzalez. "To me, after four days off, it was good. Good job for him."
Second baseman Danny Worth went 2-for-4 to lead the Astros. Luis Valbuena contributed an RBI single and Colin Moran homered.
Up next for the Astros:Carlos Correa, Jose Altuve and George Springer are expected to return to the lineup as the Astros face the Braves at 12:05 p.m. CT Tuesday at Osceola County Stadium (watch on MLB.TV). Right-hander Mike Fiers, who allowed three runs and five hits in three innings his last time out, will make his fourth start of the spring for the Astros.
Up next for the Nationals: After an off-day Tuesday, the Nationals return to action at 5:05 p.m. ET on Wednesday against the Yankees at Space Coast Stadium (watch on MLB.TV). Right-hander Stephen Strasburg makes his fourth Grapefruit League start in what should be a pitchers' duel against New York's Masahiro Tanaka.