HOUSTON -- After Adam Duvall fouled a down-and-in sinker off the back of his right foot, he had a feeling that reliever Kendall Graveman might go back to the very same spot.

And Duvall was right, smashing a go-ahead three-run home run just seconds after doubling over in pain to give the Red Sox a 7-5 win over the Astros in 10 innings on Wednesday night.

“I could barely put any weight on [my foot],” Duvall said. “But I figured he was going to go back in there with it, after me fouling it off.

“That’s kind of the chess match a little bit. I know how pitchers think -- get a guy to foul it off his foot, they know you’re tender in there. They know you don’t want to swing over another one and do the same thing.”

Not only was the homer the eventual game-winning shot and his third blast in three days, Duvall’s big hit also gave the Red Sox a huge boost in the American League Wild Card race. All three teams Boston is currently fighting for the last two AL playoff spots -- Houston, Seattle and Toronto -- lost, and the Red Sox (67-60) climbed back to four games back of the Mariners (71-56) for the final Wild Card slot.

“[This win] was better than the one on Sunday, to be honest with you,” manager Alex Cora said. “Especially with knowing everything that happened today. I’m not going to lie, we’re watching, so we gained ground.”

Facing a potential third straight loss to the Astros and dwindling postseason odds, it was as close to a must-win game for the Red Sox as they’ve played all season. Boston fell behind early, 3-0, desperately trying to claw its way back.

Starter Chris Sale made his third start since a stress reaction in his left shoulder sidelined him on June 1. He said he felt a “sense of emergency” and recovered from four runs in his first three innings for back-to-back 1-2-3 innings in the fourth and fifth to end his outing. His 19 swings-and-misses matched a season high set on April 18.

Then it was the bullpen’s turn to battle. Garrett Whitlock recorded two impressive defensive plays -- including an incredible sliding catch on a foul pop-up. Chris Martin shook off a defensive miscue -- one of many that have hurt the Red Sox this series -- and Nick Pivetta kept the game tied despite being thrust into action after closer Kenley Jansen exited with right hamstring tightness after throwing just three pitches.

Duvall finished off the comeback. After a fractured left wrist sidelined him for a few months earlier this season, the outfielder is regaining the power that led him to 30-homer seasons in 2016 and ’17 and a 38-homer campaign in ‘21.

“Just pulling the ball, staying on pitches, taking his walks,” Cora said. “We’ve been talking about the walks for a while, and when you do that, you’re giving yourself a chance to drive pitches, and right now, he’s on time and hitting the ball.”

Duvall is pulling the ball more often (55.8% in 2023 compared to 48% for his career). Combine that with an increased fly ball rate (55.1% in 2023 compared to 50.2% for his career), and the 34-year-old has matched the highest wRC+ (120) of his career by unlocking more power.

“My swing is allowing me to [pull the ball more],” Duvall said. “That’s my strength.

“I think I’m moving better, just being able to get the foot planted and be stacked and in a good position to fire. Sometimes when you lean a little too far back or get a little too far forward, then it’s hard to swing efficiently.”

Even when Duvall could barely put any weight on one of his feet, he relied on his veteran savvy to predict Graveman’s pitch and send it to the left-field seats just two days after Red Sox broadcaster Kevin Millar’s own prediction of a Duvall home run.

“[Duvall] just opened up with two strikes and sold out,” Astros manager Dusty Baker said. “He was looking for it. This guy has been around a long time. He's a smart hitter. Sometimes the nod goes to the hitter.”