CLEVELAND, Ohio — The Polar Bear growled at the right time Monday night.

Pete Alonso, nicknamed the Polar Bear, out-powered Vladimir Guerrero Jr. in the final round Monday night to win MLB's Home Run Derby at Progressive Field. Alonso won the final round, 23-22.

While Guerrero caused the excitement with one long homer after another, Alonso just kept winning. He beat the Tribe's Carlos Santana, 14-13, in the first round. He then edged Atlanta's Ronald Acuna Jr. in the semifinals, 20-19.

Guerrero out-homered Alonso 91-57 over three rounds, but Alonso emerged the winner. He is the first Mets player to win the derby outright. Darryl Strawberry shared the title with Wally Joyner in 1986.

The 91 homers are the most ever hit in derby history. They were hit by the youngest player in derby history as Guerrero participated at 20 years and 114 days.

"It's survive and advance," said Alonso. "You've got to go in with a kind of killer instinct. It doesn't matter how many you hit, you just have to have one more than they guy you're facing. I'm really happy I didn't have to swing a lot going into the extra rounds."

For the first time in derby history the winner received $1 million in prize money. When asked Monday afternoon what he would do with the money if he won, Alonso said, "Well, I'm getting married pretty soon." He also said he'd donate five percent of the award to Wounded Warriors and Tunnel to Towers programs. Wounded Warriors aids injured military personnel, while Tunnel to Towers aids the military and first responders.

The final round came down to rookies Guerrero and Alonso. Guerrero was the eighth seed in the eight-man field because he had just eight homers in 61 games with Toronto. Alonso, the second seed, hit 30 in the first half with New York.

Guerrero, whose father Vlad Guerrero Sr. won the derby in 2007, hit first in the final round. He put up 22 homers, but Alonso was one better.

The highlight of the derby came in the semifinal match between Guerrero and Joc Pederson of the Dodgers. It went to three tiebreakers before Guerrero won it on the second round of the best-of-three swings, 2-1.

Guerrero and Pederson were tied at 27 homers after their regulation four-minute sessions. They'd each earned 30 seconds of bonus time and were tied after that as well, 29-29. The rules called for a 60-second swing-off with a running clock. They each homered eight times to remain tied at 37.

The next tiebreaker called for each player to take three swings. Guerrero and Pederson each managed one homer to stay tied at 38. It finally came to an end in the final round of three swings.

Guerrero homered in his first two at-bats before popping up. Pederson homered in his first at-bat, but hit ground balls to right field on his next two swings as Guerrero advanced to the finals.

"There are so many guys that just put on a show," said Alonso. "Joc was amazing. ... Vladdy, they did such a good job. I don't want to leave anybody out. Everybody did such an amazing job just going out there and showing their stuff and showcasing young talent in the game."

Alonso is just the second rookie to win the derby. Aaron Judge of the Yankees won it in 2017.

In the first two rounds, Guerrero hit a record 69 home runs.

Alonso, who slipped past Santana in the first round, advanced to the finals with another close victory over Atlanta's Ronald Acuna Jr. Alonso was trailing 19-8 when he called time with 1:49 left. He then hammered 12 homers before time expired to win, 20-19.

Guerrero, Pederson, Acuna Jr. and Alonso advanced to the semifinals out of the original eight-man field.

Oakland's Matt Chapman — the fill-in for Milwaukee's Christian Yelich — fell to Guerrero in the first round, 29-13. Pederson beat Houston's Alex Bregman, 20-16. Acuna beat Pittsburgh's Josh Bell, 25-18.

Santana started slowly against Alonso and called time with just five homers and 1:44 left. He added eight more before time ran out, but didn't earn the 30-second bonus time because had had only one homer over 440 feet.

Alonso, with just under 10 seconds left, hit his 14th homer to beat Santana.

The soldout crowd of 36,119 booed Alonso when he was introduced because he was facing Santana. Alonso took the booing in stride.

"I didn't think I'd ever be booed at a Home Run Derby, to be honest with you," said Alonso. "But I guess that's the hometown home cooking."

Guerrero led all hitters in the first round with 29 homers. He hit 22 in the regular four-minute period and seven more in bonus time. A hitter earns bonus time if he hits two or more homers over 440 feet. On his first home run of the round, Guerrero hit the corner of the scoreboard above left field.

Finally, Alonso was asked how he got the nickname Polar Bear.

"In spring training Todd Frazier told me, 'You look like a big old polar bear,'" said Alonso. "And then it just kind of stuck.'"

So did the Home Run Derby title.