CLEVELAND — The Guardians have won with comebacks and walk-offs for months, turning an unexpected season more special by the day.

Cleveland wasn’t supposed to be this good, this fast.

Baseball’s youngest team certainly has grown up.

Rookie Oscar Gonzalez broke up the longest scoreless postseason game in history with a leadoff home run in the 15th inning, giving the Guardians a 1-0 win in Game 2 over the Tampa Bay Rays and sweep of the Wild Card Series.

Gonzalez, who walks to the plate to the “SpongeBob SquarePants” theme song, drove a 1-0 cutter – the 432nd pitch in the nearly five-hour game – off Corey Kluber over the wall in left-center to touch off a wild celebration.

As Gonzalez rounded the bases, and his teammates gathered near home plate to greet him, the sellout crowd of 34,971 fans shook Progressive Field as Cleveland’s surprise season added a story book chapter.

“There’s no way to describe it,” said Gonzalez, who punctuated his shot with an emphatic bat flip before strutting toward first. “It was such an exciting moment that it’s hard for me to put into words.”

Now, the Guardians, who have had been fun-loving, free and fearless since opening day, start the best-of-five Division Series on Tuesday in New York against the AL East champion New York Yankees.

On their visit to Yankee Stadium in April, the Guardians were swept and trash was thrown at them.

They’re returning a different team.

Guardians President of Baseball Operations Chris Antonetti isn’t buying any David vs. Goliath storyline.

“We haven’t gotten caught up with that and what the external narrative has been around our team,” he said. “These guys have written their own story.

“The Yankees are obviously a great team and we know we have our work cut out for us, but these guys embrace the challenge.”

Cleveland has defied odds in its first season after adopting the Guardians nickname. The team ran away in the AL Central by going 24-6 down the stretch, swept the more experienced Rays and now take on the Yankees with their big bats and bigger payroll ($254 million to Cleveland’s $68 million).

Gonzalez was among 17 players to make their debut for the Guardians this season, so perhaps it was fitting he advanced them.

“I don’t think by that point we cared,” Manager Terry Francona said. “It could have been one of the old guys. We didn’t care. We’re not biased. I was happy that he hit it.”

MARINERS 10, BLUE JAYS 9: Adam Frazier hit a tiebreaking RBI double in the ninth inning, and Seattle erased a seven-run deficit while topping Toronto for a sweep of their AL wild-card series.

It was the biggest road comeback win in playoff history and baseball’s largest comeback victory to clinch a postseason series. Next up for resilient Seattle is Houston in the AL Division Series.

Making the franchise’s first playoff appearance since 2001, Seattle trailed 8-1 through five innings, but it tied it at 9 with four runs in the eighth.

With two out and the bases loaded, J.P. Crawford hit a blooper to center against All-Star closer Jordan Romano. Center fielder George Springer and shortstop Bo Bichette went hard after the ball, but it landed as the two collided. All three runners scored on the double, tying it at 9.

It looked as if Bichette’s right arm whacked Springer across the forehead. Bichette got up pretty quickly and stayed in the game after he was checked on by a trainer. A woozy Springer was helped to his feet before he was carted off the field.

The 33-year-old Springer, a four-time All-Star, encouraged the cheering crowd as he was driven off.

Cal Raleigh, who hit an RBI single for Seattle in the eighth, reached on a one-out double against Romano in the ninth. After Mitch Haniger flied out, Frazier drove in Raleigh with a double to right.