Violet Palmer became the first woman to referee an NBA game in 1997. Sarah Thomas was the first female to officiate an NFL game in 2015. In 2022, Stephanie Frappart became the first woman referee in a World Cup match. Baseball finally broke its gender barrier on Saturday when Jen Pawol became the first woman to umpire a regular-season major league baseball game.

Ms. Pawol, 48, made her debut as the first base umpire in the first game of a double-header between the Atlanta Braves and Miami Marlins at Atlanta. She worked third base in the second game, and on Sunday afternoon was behind the plate calling balls and strikes.

“She’s got to be tough as nails,” Ray Birmingham, a long-time college and former USA baseball coach, tells the Sun. “It’s not an easy job.”

Her historic debut was uneventful, just the way umpires like it. As the first base umpire, her job was to check the starting pitcher’s hands for foreign substance after each inning. Braves right-hander Hurston Waldrep offered a smile when she checked his hands in the first inning. She also received a warm greeting from Braves catcher Sean Murphy.

Her first close play came in the third inning when she called Mr. Murphy safe at first when replays showed he may have been out. Marlins manager Clayton McCullough didn’t argue the call. Fans at Truist also acknowledged Ms. Pawol with a warm ovation when she was featured on the video board.

Ms. Pawol was called up to the big leagues after working more than 1,200 minor league games at every level for nearly 10 seasons. A New Jersey native who starred in softball at Hofstra University, Ms. Pawol was a softball umpire from 2010 to 2016. In 2015, she accepted an invitation to attend a MLB tryout camp for umpires and was impressive enough to earn a spot at the Umpire Training Academy later that year in Vero Beach, Florida.

In the spring of 2016, she began calling games in the Gulf Coast League. She worked her way up the minor leagues and showed enough promise and dedication to be assigned to the Triple-A Championship Game in 2023. In 2024 and 2025, she prepped for the big leagues by calling major league spring training games.

“Umpiring is for me,” Ms. Pawol said recently. “It’s in my DNA. It’s been a long hard journey to the top. But I just love the camaraderie with my crew, with the fellow umpires. I love the travel. I love working out. There’s so many similarities being an athlete and an umpire, and I never have to leave the field when I’m umpiring. I’m just extremely focused on getting my calls right. I’m so grateful to all those along the way who helped me become a better umpire every day.”

Unlike other major sports, baseball took the slow route to breaking its gender barrier among umpires. When she began calling minor league games, she was the first woman to do so since Shanna Kook in 2003-2004 and only the seventh ever. Bernice Gera was the first in 1972, followed by Christine Wren (1975-1977), Pam Postema (1977-1989) Theresa Cox Fairlady (1989-1991) and Ria Cortesio (1999-2007).  None of those women got the opportunity to call a regular-season major league game.

Mses. Gera, Postema and Cox took legal action to get their opportunities. “The women who came before me, they moved some big boulders to make it easier for women to come through,” Ms. Pawol said. “I’m just so grateful for what I get to do for a living. I love it.”

MLB Commissioner Robert D. Manfred Jr. called Ms. Pawol’s major-league debut an “historic accomplishment,” and credited her “hard work, dedication and love of the game.”

The fans in Atlanta understood they were witnessing baseball sports history. Some held up signs that read, “Welcome to the Show, Jen” and “Thank you, Jen! From girls and women everywhere.”

Ms. Pawol understands she is now part of sports trivia history. “I’m aware of the gravity,” she said. “I’m aware of the magnitude. “I believe that I’m going to be a very good steward and representative for young girls and women, and boys and men, that this is possible.”