BOSTON

The Houston Astros poured back onto the field after advancing to their first AL Championship Series, posing for pictures with the Green Monster as a backdrop before a few players belly-flopped in the puddles in the infield dirt.

No matter, they were already soaked from celebratory beer and sparkling wine after a 5-4 win and a 3-1 series victory over the Red Sox.

Justin Verlander, who was acquired for the playoff run after spending his first 13 seasons in Detroit, gave up the go-ahead homer to Andrew Benintendi — the first batter he faced — before shutting Boston down for the next 2 2/3 innings.

The former AL MVP and Cy Young winner earned the victory in his first relief appearance after 424 starts in a major and minor league career.

The Astros will open the ALCS on Friday, either at Cleveland or at home against the New York Yankees.

The Red Sox forced a Game 4 after losing the first two games in Houston, and then took a 3-2 lead in the fifth on Benintendi’s homer. Bregman tied it before Reddick’s single off closer Craig Kimbrel made it 4-3.

Carlos Beltran added to his postseason legacy with an RBI double in the ninth — an insurance run that became the game-winner when Rafael Devers hit an inside-the-park homer off closer Ken Giles over leaping center fielder George Springer and off the Green Monster toward center.

The 20-year-old Red Sox rookie easily circled the bases before the throw to make it 5- 4.

Giles retired the next three batters for the six-out save.

The Astros last reached the league championship series in 2005 as a National League team, and were swept in the World Series by the White Sox.