Boston Red Sox designated hitter J.D. Martinez celebrates with Rafael Devers after hitting a grand slam against the Houston Astros during the first inning in Game 2 of baseball's American League Championship Series Saturday, Oct. 16, 2021, in Houston. (Kevin M. Cox/The Galveston County Daily News via AP)

HOUSTON — J.D. Martinez and Rafael Devers helped the Red Sox have a grand old time in Houston.

Boston became the first team to slug two grand slams in a postseason game, with Martinez and Devers connecting in the first two innings of a 9-5 win over the Astros on Saturday that tied their American League Championship Series at one game apiece.

Martinez made it 4-0 with his opposite-field shot off rookie Luis García with two outs in the first. It was the first career playoff slam for the four-time All-Star, who began his career with the Astros.

García exited with right knee discomfort after walking the first batter of the second inning. Jake Odorizzi took over, and shortly after a 13-minute delay while the right-hander warmed up on the field, Devers connected with one out for slam No. 2.

“J.D.’s swing was huge to get us on the board early, and then Raffy, same thing, another granny,” red-hot teammate Kiké Hernández said. “Has that ever happened before?”

It has now.

Game 3 is Monday night in Boston. It’s the first of three consecutive home games for the Red Sox, back in the playoffs for the first time since winning the 2018 World Series after downing Houston in the ALCS.

Hernández, who Boston manager Alex Cora referred to Friday night as “en fuego” after a two-homer performance in Game 1, remained on fire Saturday. He had two hits, highlighted by a solo homer in the fourth inning.

Red Sox starter Nathan Eovaldi permitted five hits and three runs in 5 1/3 innings.

The Astros captured a 5-4 win in the series opener as they rallied behind homers from Jose Altuve and Carlos Correa before falling into the huge hole early in this one.

The Red Sox were up 9-0 when Houston got on the board with an RBI double by Kyle Tucker with two outs in the fourth. The Astros cut the lead to 9-3 when Yuli Gurriel followed with single to right field that scored two more.

Gurriel and Jason Castro added solo homers in the ninth off Darwinzon Hernandez before Ryan Brasier got the final out.

“At the end, it was a little too close for comfort, but we got it done,” Hernández said.

The injury to García is another blow to a Houston team trying to reach the World Series for the second time in three years. The Astros are already reeling after an injury to staff ace Lance McCullers Jr. that kept him off the roster for this series.

When McCullers went out, manager Dusty Baker said the team would just have to “hit more” to absorb the loss. But now that the rotation is further depleted, it’ll be an even taller task for this powerful lineup outgunning a Boston team whose offense has outpaced everyone this postseason.

Odorizzi was left off the Division Series roster after a disappointing first season in Houston before getting a spot in this round after the injury to McCullers. He allowed seven hits and four runs in four innings Saturday in a performance that certainly isn’t good news for a team that is running short on starters.

Story by Kristie Rieken.