The 12-year-old pitcher didn't seem as confident when he got the last out to win the Little League World Series, letting out a huge sigh of relief.
Alvey hit a 250-foot shot in the first inning and set two pitching records and tied a third as Louisville, Ky., beat Sendai, Japan, 1-0 on Sunday night for the championship.
"It was 68 mph down the middle," Alvey said. "It was belt-high, so it was going to get crushed."
Then, with two out in the sixth inning, a clearly nervous Alvey walked Yoosuke Katoh, bringing up Tatsuhiko Numakura, who had three home runs in the series. But Numakura's line drive was caught by first baseman Casey Jordan to end the game.
"I was like, 'Have I got it? Have I got it?"' Jordan said. "I just had to pull it down, see it first."
Alvey struck out 11 on his way to setting World Series records for strikeouts (44) and scoreless innings (21) and tying the mark for consecutive no-hit innings (12).
Louisville is the first U.S. team to win the title since Toms River, N.J., beat Kashima, Japan, 12-9 in 1998.
"Me and my teammates worked really hard since it started," Alvey said. "Me and my teammates are really, really happy that this happened."
Alvey experienced shoulder pain midway through the game, and received heat treatments in the dugout.
"My shoulder starting hurting a little bit ... then it started feeling good," said Alvey. "I went back out there to do my thing."
"Aaron pitched a tremendous game, there's no question. But our defense stepped up again tonight," Louisville manager J. Troy Osborne said. "There were several balls out there today that Josh (Robinson) handled, plus the big one at the end of the ballgame. Casey did a tremendous job. If that ball gets to right field, as fast as they are, they're going to score."
Alvey struck out Yoshinori Satoh in the second to break the 31-year-old record for strikeouts. Mu-Hsu Chin of Tainan City, Taiwan, struck out 36 in two games in 1971, including 22 in nine innings in Tainan City's 12-3 championship victory over Gary, Ind.
Alvey tied the record with 12 consecutive no-hit innings - one against Clemmons, N.C., nine against Fort Worth, Texas, and the first two against Japan. Sean Burroughs also had 12 consecutive no-hit innings in 1993 for champion Long Beach, Calif.
On Wednesday night, Alvey threw a no-hitter through nine innings in Louisville's 2-1, 11-inning victory over Fort Worth in the U.S. semifinals. Although Little League rules required that Alvey be replaced in the 10th inning, his performance was recorded as a no-hitter, the longest no-hitter in Little League history.
Before Yuuki Chiba's line drive to center field to lead off the third, the last hit Alvey allowed was Andrew Biancardi's infield single leading off the sixth inning for Aptos in Louisville's Aug. 17 series opener.
The last run Alvey allowed scored on Biancardi's RBI double in the first. Burroughs had shared that record with Art Deras, who pitched for Hamtramck, Mich., in 1959.
This being Little League, no game would be complete without the reaction of the parents.
Kim and Troy Alvey were on hand in Williamsport and bursting with pride when the big moment came. Kim found herself speechless, but not Troy.
"I knew he was special from the day he was born," said Alvey's dad. "Now all my dreams have come true right here on this field."