Bradley stepped up to the plate with Christian Vazquez standing on second base and the Red Sox trailing 5-4. He swatted the first offering he saw from Josh James over the right field fence for a 385-foot home run. The bomb had an exit velocity of 104-mph, according to Statcast.
The Red Sox added a two runs over the final three innings, while allowing one Astros score, to secure the victory and earn a 3-1 lead in the series. Boston will clinch a spot in the World Series with a win in Game 5.
"It was a big momentum shift," Bradley told reporters. "They took the lead and to be able to take it back, I felt the energy from my teammates. It was a big moment for us. We never feel like enough runs is going to be enough. We want to continue to put it on, because they're a very good ball team."
Rafael Devers gave Boston its initial lead, plating two scores on an RBI single in the top of the first inning. But Carlos Correa helped the Astros cut the lead in half with an RBI single in the bottom of the second frame.
Xander Bogearts doubled in Andrew Benintendi in the top of the third inning to give Boston a 3-1 advantage, before Houston answered once again. George Springer led off the bottom of the third inning with a solo home run. Josh Reddick tied the score with an RBI single in the same frame.
The Astros went ahead 4-3 on a solo home run by Tony Kemp in the bottom of the fourth inning. Bogaerts smacked an RBI single in the next inning, tying the score at 4-4.
Correa returned to the plate in the bottom of the fifth inning, providing an RBI single and grabbing the lead back for Houston.
Then Bradley came to the plate, going yard and bringing in the go-ahead runs in the sixth inning. Brock Holt walked with the bases loaded in the next inning, giving Boston a 7-5 advantage. J.D. Martinez brought in Mookie Betts with an RBI single in the eighth inning for Boston's final run.
"I'm very proud of [Bradley], what he's done in the second part of the season and what he's done tonight and in this series," Red Sox manager Alex Cora said. "It's amazing. He keeps working on his craft, his swing. He understands now, he's staying through the ball, hitting the ball in the air. There's no more hitting line drives into the shift. Now he hits the ball in the air."
Game 5 of the 2018 ALCS is set for 8:09 p.m. on Thursday at Minute Maid Park in Houston.
Moments from the MLB post-season