BOSTON -- Alex Bregman's postseason career is merely five days old, and the 23-year-old Astro is already posing as an October vet.
"He is light-years ahead of a regular 23-year-old," Houston catcher Brian McCann said. "He shows up every day, and you know what you're getting out of Alex Bregman. He loves the game of baseball probably more than anybody I've ever been around. He owns the moment."
The moment, on this day, could not have been bigger.
McCann and the Astros reveled in a celebration largely concocted by Bregman's big blast. The third baseman's game-tying home run against Red Sox left-hander Chris Sale in the eighth inning of Houston's 5-4 victory, which clinched a series win in the American League Division Series presented by Doosan, is the stuff of dreams, not doings.
"It is, it's what you dream about," Bregman said. "I grew up watching playoff games at Fenway when David Ortiz was getting clutch hits. This is what you live for."
Bregman, of course, did not act alone. These Astros players never do. Young and old make up this uniquely built unit, all parts forming a total team effort that's been on display all year. It's largely what got them to the point of Bregman's game-changing at-bat. They are now on to the AL Championship Series presented by Camping World against the Yankees or Indians. That series will begin Friday, and the Astros will host Game 1 vs. the Yankees.
Game 4 against Boston saw AL batting champion and Most Valuable Player Award candidate Jose Altuve go hitless for the first time in the series. Phenom Carlos Correa struck out three times, as did McCann. It didn't matter.
"Someone new steps up every day," outfielder Josh Reddick said. "That's just how it's been all year. Our lineup's pretty special, and what we can do one through nine is pretty magnificent."
Last winter, following a disappointing season that did not reach the playoffs, Houston's decision-makers wanted to surround its young core with an impact group of veterans. So they went out and traded for McCann, and signed Reddick and Carlos Beltran, the latter two of whom came up just as big as Bregman on Monday.
After Bregman launched his home run over the Green Monster, Evan Gattis reached on a single with one out, and Sale would only be asked to stick around for a second out, with Boston hoping to restore order with closer Craig Kimbrel.
Kimbrel's dominance has been well-documented this season; his regular-season credentials included a 1.43 ERA and a 0.681 WHIP. But this Astros lineup, too, is exceptional, and George Springer quickly worked a walk to bring Reddick to the plate with two men, including pinch-runner Cameron Maybin at second, aboard. Reddick forced a full count, fouling off consecutive pitches eclipsing 99 mph. He got another, at 99.3 mph, and slapped a single through the left side for a 4-3 Astros lead.
Not once had Kimbrel yielded a go-ahead hit this season.
"I was telling [Justin] Verlander in the dugout, I didn't want anybody else up but Reddick right there," Bregman said. "I knew he was going to come through."
"He's such a tough at-bat," Verlander said. "He doesn't give in, just finds a way to get the job done."
Beltran, meanwhile, has been known to deliver similar acts in the postseason (most notably during his first stint with the Astros in 2004), and he was asked to do so again in the ninth inning. The Astros, seeking an insurance run for closer Ken Giles, who would provide them two innings, sent Beltran to the plate as a pinch-hitter with two on and two out against Kimbrel.
Beltran blasted a double off the Green Monster, knocking Kimbrel out of the game and upping his already stellar postseason average to .325 (65-for-200) and his RBI total to 42. Only Steve Garvey (.338) has a higher mark in Major League history among batters with at least 200 at-bats.
The 40-year-old's two-bagger was the deciding factor in a game that saw Boston's Rafael Devers lead off the home half of the ninth with an inside-the-park home run.
"We've got a little bit of everything," Astros starter Dallas Keuchel said. "The young guys have learned from the older guys, and that's what it's going to take to win a championship -- guys who have done it before like Beltran, who has one of the best postseason careers in history."
Said Beltran: "This is what we have played for all season long. I feel proud of the whole team and look forward to what's ahead of us."
Jane Lee is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.