Kiké Hernández lifted a sacrifice fly to give the Boston Red Sox their second straight walk-off victory and eliminate the Tampa Bay Rays, ending a heart-stopping ALDS.

The 100-win Rays, champions of the daunting AL East, watched their shot at defending their 2020 pennant slip away at Fenway Park on Monday night as the Red Sox advanced to the ALCS with a 6-5 win in Game 4.

Steered by former Rays executive Chaim Bloom and once again managed by Alex Cora in his first season back after a sign-stealing suspension, the Red Sox came into 2021 looking like they were in the middle of reloading, if not rebuilding. The 2020 team had managed to finish last in an AL East that also included the Baltimore Orioles. But with a hot start, they announced their presence in a division that ultimately produced four 90-win teams and three postseason teams.

After securing a home wild-card game in the final weekend and then knocking out the New York Yankees, they have now upended the Rays and will march on as the last AL East contender standing.

Early on in Game 4, it looked as if the Red Sox may even punch their ALCS tickets with little drama. Rafael Devers’ three-run homer in the third inning highlighted an epic two-out barrage that put the Rays in a deep hole.

With both teams improvising on the pitching front after Sunday’s marathon Game 3, the Rays had summoned Game 1 starter Shane McClanahan to work in relief. The rookie lefty was clearly not sharp on this occasion after a strong performance in the series opener, quickly allowing two baserunners. He had gotten to two outs without surrendering damage, but then Devers stepped in and obliterated a 97.7 mph fastball that McClanahan right in the middle of the zone. Xander Bogaerts, Alex Verdugo and J.D. Martinez rattled off three consecutive hits following the homer, notching two more runs to chase McClanahan.

Opposite the Rays’ search for steady work on the mound, Boston’s Eduardo Rodriguez delivered. After a rough Game 1 start, he returned for Game 4 and gave manager Alex Cora a much easier roadmap to a win by firing 5+ innings, allowing only three hits and two runs, striking out six with no walks.

But the Rays, in an echo of Game 3, roared back against the Red Sox bullpen. Wander Franco smashed a two-run homer in the sixth, and then Kevin Kiermaier and Randy Arozarena came up big to tie the game in the top of the eighth.

In the bottom of the frame, the Red Sox were threatening to retake the lead until Kiermaier zipped a throw to third base to nail Verdugo trying to advance on a flyout.

Garrett Whitlock, a rookie the Red Sox poached from the Yankees in the offseason’s Rule 5 draft, firmed up Boston’s pitching with two scoreless innings to keep the game tied. In the bottom of the ninth, Sunday night hero Christian Vazquez singled, was bunted over to second and advanced to third on a ground ball before he was lifted for pinch-runner Danny Santana.

That brought up Hernández — who sparked the rollicking Red Sox offense by collecting hits in seven straight plate appearances earlier in the series. He guided an 0-1 fastball deep into center field, giving Santana plenty of time to tag up and race home to begin the celebration.

Now the Red Sox will await either the Houston Astros or Chicago White Sox. After guiding the 108-win 2018 team through a dominant World Series run, Cora is now 15-4 as a manager in postseason games. As skepticism remains around the Astros, Cora could be set up to face the club where he coached and spearheaded the illicit sign-stealing scheme that led to his suspension.

For Bloom, Boston’s chief baseball officer, the victory is a triumph over his former employer. As more and more Rays front office personnel take over other clubs, Tampa is becoming familiar with the taste of losing to former friends. Former general manager Andrew Friedman led the Los Angeles Dodgers to a World Series win over the Rays in 2020.