Nationals 3, Astros 2: Wilson Ramos’ eighth-inning sacrifice fly capped a two-run rally as host Washington continued its red-hot start.

Jayson Werth set up the game-winner by drawing a bases-loaded walk to tie it 2-2.

At 10-3, the Nats are off to the franchise’s best start since the 1981 Montreal Expos opened 11-2. Henry Rodriguez pitched a 1-2-3 ninth for his third save in as many chances.

Houston leadoff hitter Jordan Schafer had given the Astros a 2-1 lead in the eighth with an RBI single.

Washington starter Jordan Zimmermann, whose 2.8 run-support average since the start of last season is the worst in baseball, allowed one run over seven innings but got a no-decision. Houston’s Lucas Harrell, making his eighth career start, nearly matched him, allowing one run over 6 2/3 innings.

Left fielder Travis Buck’s RBI groundout gave the Astros a 1-0 fourth-inning lead, but he left shortly thereafter with a groin injury. Washington tied it 1-1 in the seventh on doubles by Rick Ankiel and Roger Bernadina.

Game Notebook: Zimmermann, who did not walk a batter, remains winless despite a 1.29 ERA. … Schafer swiped his sixth base in a two-hit night that pushed his on-base percentage over .400. … The Nats improved to 6-1 at home.