BAYONNE, N.J. -- On the pitcher's mound, a 12-year-old girl from New Jersey is perfect.

Mackenzie Brown is the first girl in Bayonne Little League history to throw a perfect game. She retired all 18 boys she faced on Tuesday, striking out 12, including the last six batters she faced, according to The Star-Ledger of Newark.

There are no official records of how many perfect games are thrown per season. Little League Baseball in Williamsport, Pa., estimates only 50 to 60 occur each year. No one knows how many have been thrown by girls.

"In like the fourth inning I kind of knew," she said, according to the Star-Ledger. "Then I just tried to keep doing what I was doing and not try to mess it up."

The closest she came to losing the perfect game was on the second-to-last batter, who fouled off numerous pitches, according to the report. She eventually struck him out.

She'll get to throw out the first pitch at Citi Field on Saturday when the New York Mets host the Washington Nationals.

"It's been pretty crazy," she said, according to The Star-Ledger. "In school I have all these teachers asking for my autograph. I wasn't used to that."

Although the perfect game has earned her national attention, including television interviews and seeing her own highlight reel on TV, Brown said the best thing about it is "probably just being able to throw like that," according to the newspaper.

"There are some players I might worry about if their hats would fit on their heads by the time I needed them to pitch again," said her manager, Glenn Regan, according to the report. "But not Mackenzie."

Information from The Associated Press was used in this report.