CLEVELAND -- Miguel Sanó unleashed a season’s worth of bases-loaded frustration for the Minnesota Twins with one mighty swing of his bat. It also dealt a crushing blow to the Indians’ hopes for the American League Central crown.

It only took Sano one pitch from Cleveland reliever Nick Goody to unload on a slider over the inner half for a grand slam that capped a five-run rally in the eighth and seemingly sucked the air out of Progressive Field. The blast powered a come-from-behind, 9-5 victory for the Twins that secured a sweep of Saturday’s doubleheader and moved Minnesota’s lead in the AL Central to 5 1/2 games.

• Box score

“It’s a tremendous swing in a very challenging, dramatic moment,” Twins manager Rocco Baldelli said. “Something big was needed. These are really emotional, big games. These games are fun; they’re a different brand of baseball this time of year, and that’s just a huge play and a huge swing. It kind of put us in position to win the game, flat out.”

Entering Saturday, the Twins looked to face an uphill battle against their challengers for the division crown, as they needed to piece together 18 innings from their bullpen while facing dominant right-hander Mike Clevinger in one of the contests.

First, they blasted their way past Clevinger in a 2-0 win. Then, they bombed through Cleveland’s bullpen.

Now, the Twins are guaranteed to leave Cleveland with a lead no smaller than 4 1/2 games with only Chicago, Kansas City and Detroit remaining on the schedule.

"That's a big day,” Sano said. “It's a big day for everybody here -- for the staff, for the players and for the fans. Everybody's happy here. We played the game. We never put our heads down. We came here to compete and win the game."

“It doesn’t matter how long the day is if we win games,” Jorge Polanco said.

The Twins faced an early 5-2 hole after a tough start from Lewis Thorpe but pulled to within one run on a two-run blast by Nelson Cruz in the sixth -- and the real fireworks came in the eighth.

After Max Kepler moved to second base on a throwing error by Francisco Lindor, Polanco tied the game with a double off the left-field wall -- after he hit the go-ahead homer and made a game-saving defensive play during the first game of the doubleheader.

Cruz and Eddie Rosario, who hit a two-run homer in the first, followed with walks to load the bases for Sano, who crushed his first career grand slam -- and only the Twins’ second of the season -- a Statcast-projected 415 feet into the left-field bleachers.

"I just tried to hit the ball and tried to get some guys to the plate,” Sano said. “The guy made a mistake. He threw me a [slider] down the middle, and I had the chance to hit the homer."

Sano’s grand slam was particularly significant in light of the Twins’ season-long struggles with the bases loaded.

Though Minnesota entered the day with 279 homers after having broken the all-time Major League record earlier this season, the Twins were also slashing a meager .211/.216/.312 with the bases loaded, good for an MLB-worst .528 OPS and 28 wRC+ in such situations.

“There's nothing to point to,” Baldelli said. “Nothing I know of. We have good hitters. They hit well with people on base. When there's three people on base, you hope they hit even better. We haven't to this point, but maybe we're due.”

None of the heroics would have been possible without a titanic day from the Twins’ bullpen.

The Twins went into the day needing to pull 18 innings out of their hat. They ultimately needed just nine pitchers to do it, leaving six more rested relievers with whom to scrape together another bullpen game for Sunday’s series finale.

After Devin Smeltzer, Zack Littell, Tyler Duffey, Sergio Romo and Taylor Rogers combined for a five-hit shutout in the matinee victory, Cody Stashak, Brusdar Graterol and Trevor May pitched 5 1/3 more frames of scoreless relief in the nightcap. Graterol set the record for the Twins’ fastest pitch in the pitch-tracking era -- 101.9 mph -- as he earned his first career win with two perfect innings of relief.

“We needed all of them and everybody delivered,” Baldelli said. “Without pretty much everybody that was out there over the course of the day, Game 1 and Game 2, we don't win. We needed everybody.”

The Twins’ bullpen certainly experienced its ups and downs throughout the season, with personnel shifts, role changes, mechanical adjustments and periods of difficulty marking its journey to this point.

On Saturday, that relief corps faced its stiffest test -- and dominated in one of the most important moments of the regular season.

In fact, the Twins’ bullpen has been one of the best units in baseball since the start of August, lowering its collective ERA during that period to 3.57 -- the second-best mark in the AL -- with 11 1/3 scoreless innings of relief over the two games of Saturday’s doubleheader.

“It's just huge,” Smeltzer said after throwing three scoreless frames in Game 1. “It's September baseball, and in my eyes, this is playoff baseball. There's not going to be much more tension than this. We're playing a team we're fighting to stay ahead of, and we have a really deep bullpen with a lot of good arms. We just passed the baton and kept attacking.”

A division championship now appears within the grasp of these Twins. But you won’t hear them acknowledge that -- not even after a long, wildly successful day at work.

“No. We have a long way to go,” Baldelli said. “We’ll get ready to play tomorrow. We’ll start there again. And I don’t think at any point -- that won’t change at any point going forward. We play for today.”