NEW YORK -- The three hardest pitches that Rafael Devers had ever seen quickly made him aware of the challenge he was up against while facing Aroldis Chapman with the Red Sox down by a run in the top of the ninth inning on Sunday night at Yankee Stadium.

When the fourth came in, the 20-year-old Devers was ready, and he smashed the 102.8-mph offering for a stunning, game-tying solo shot to left-center that sparked the Red Sox to a thrilling, 3-2 victory over the Yankees in 10 innings.

• 5 amazing facts about Devers' homer

The 1-2 offering from Chapman was the hardest pitch any player has homered off since MLB started officially tracking pitch velocity in 2008. It was just the second homer Chapman has allowed to a lefty in his career. The first came against former Oriole Luke Scott at Camden Yards on June 26, 2011, during Chapman's second big league season.

"I was thinking hit the ball up the middle, but you can't plan a home run," said Devers. "He's just like any other pitcher. Obviously he's an All-Star. I didn't know that stat, but I just go about every at-bat the same."

Chapman was admittedly a little stunned.

"Yes, a little bit, especially being a left-handed batter there," Chapman said. "I think it's been a while since a lefty has hit a homer off me. He is a good young player who was able to take advantage of a high pitch there and made good contact."

In his first three weeks with the Red Sox, Devers has proved to be unflappable, and this was the most impressive demonstration yet.

"Yeah, an incredible swing off a 100-mph-plus fastball," said Red Sox manager John Farrell. "He doesn't fear the moment. He's jumped feet-first into this rivalry, and it couldn't come at a better time."

It was an important swing victory in the standings, as the Red Sox increased their lead over the Yankees to a season-high 5 1/2 games in the American League East.

"It's huge," said left fielder Andrew Benintendi. "We get there, we're down one in the ninth, Chapman is in there and there was an out already. Devers, huge at-bat. It's not easy to stand in there with a guy throwing 103, so it just kind of shows you the player that Devers is."

The first pitch was a 102.4-mph heater for a called strike. Devers watched ball one go by at 102-mph and foul tipped a 102.1-mph fastball for strike two. But he roped the one that counted. According to Statcast, Devers' home run off Chapman left the bat with an exit velocity of 105.9 mph, and traveled a projected 423 feet.

"I've seen 100, but never 103," said Devers. "Just let him throw pitches, see pitches and hit the one that I like."

For the Red Sox, the blast is sure to go down as one of their signature highlights of the season.

"I literally jumped up when he hit it," said Red Sox lefty Chris Sale, who fired seven dazzling innings. "I was in the trainer's room doing some work and, I mean, you can't help but smile. Talk about a moment in a game, for a guy like him, a young guy, a rookie, it's huge, and that's why you love him. That's why he's here, and those are the things we've almost come to expect out of him."

Devers clapped with joy as he rounded the bases following his first big rivalry moment.

"Yeah, this is one of the biggest rivalries that there are in sports," said Devers. "The fans get into it, and it's something that I would watch it on TV and see how tense it could get. But being here and seeing how the fans react and how each team reacts to each other is big.

"For me, it's different because there's a lot more people in the stands at these games. That made me a bit nervous in the first couple of games in the series, just knowing how many people there are in the seats. But after I got to settle in, I felt pretty good."

When the Red Sox promoted Devers from Triple-A Pawtucket on July 24, they projected he could handle the pressure of playing in a pennant race and hoped he would adapt quickly to Major League pitching. Thus far, they were right on both fronts.

In his first 15 games, Devers is slashing .328/.391/.586 with four homers and 10 RBIs.

"We've talked all along, as Raffy has continued to compile at-bats, there's a presence in the moment," said Farrell. "There's calmness. He doesn't seem to be fazed by the stage."