The first pitch of Friday night’s Sonoma Stompers baseball game was a breaking ball that went over the plate and into professional baseball history.

The pitch itself wasn’t that special, but the called strike was thrown by a woman, one of two who started the game for the Stompers against the San Rafael Pacifics at Arnold Field in Sonoma. It is believed to be the first time in more than 60 years that a team with more than one woman has participated in a professional baseball game.



Stacy Piagno, the 25-year-old pitcher from St. Augustine, Florida, made it through the first inning, gave up two runs in the second and lasted until the third inning. Behind her, in left field, was Kelsie Whitmore, 17, of Temecula (Riverside County), who Stompers officials consider the best female baseball player in the country.

“It’s exciting. I’ve got goosebumps,” said Lizette Dalquie, 64, of Sonoma, as she sat in the stands waiting for the first two female ballplayers in the independent Pacific Association to take the field. “It’s a breakthrough for the girls. The Stompers have opened the door for them and hopefully it will open up more doors.”

It wasn’t an All-Star performance for either player — Piagno gave up three hits, including two RBI doubles, and walked two. Two errors were also committed behind her. Whitmore walked and struck out in two plate appearances and the Stompers lost 8-4.

What’s important, though, is that they fit right in with the guys, said Theo Fightmaster, the Stompers’ general manager.

“They’re ballplayers,” Fightmaster said. “This is a big deal to me and it’s also a big deal because the game of baseball hasn’t done a great job of including women and giving girls a chance to play the game. The mission here is the advancement of women in baseball at all levels from Little League to the major leagues.”

The bright idea to recruit women was first floated by film director Francis Ford Coppola, who said in a news release that he always wondered why there weren’t co-ed teams in professional baseball given that the game doesn’t rely as much on size and strength as other sports.

“My family would play co-ed baseball games and inevitably the star player would always be an aunt,” said Coppola, whose Virginia Dare Winery, in Geyserville, has been a primary sponsor of the team over the past three years. “So when my Sonoma winery became involved with the Stompers, I had the opportunity to turn this thought into a reality and recruit these amazing women capable of playing alongside men.”

The women eventually picked are no slouches. Team officials scouted Piagno and Whitmore at the tryouts for Team USA, which is scheduled to play in the Women’s Baseball World Cup in South Korea this fall. Piagno no-hit Puerto Rico at the 2015 Pan Am Games and was a softball player at the University of Tampa. Whitmore, who recently graduated from high school, will attend Cal State Fullerton on a softball scholarship this coming year.

Both played baseball against boys in high school.

It isn’t the first time women have played baseball with or against men. The most famous mixing of the sexes occurred in the mid-1990s when famous knuckleball pitcher Phil Niekro recruited the best female ballplayers in the country to play for the Colorado Silver Bullets.

The team, which was made up mostly of top college softball players, went up against minor-league and college teams at first, taking a few shellackings before lowering expectations. Later, they competed against lower level men’s teams and had a winning record in 1997, their last year before the Coors Brewing Company chose not to renew their sponsorship.

Two women, Ila Borders and Eri Yoshida, have pitched in professional baseball in the United States in recent years, but the Stompers are believed to be the first team with more than one woman playing in the U.S. since three women played in the Negro Leagues in the 1950s.

The Stompers have, in fact, been unusually progressive since the team was founded in 2014. Stompers pitcher Sean Conroy became the first openly gay professional baseball player in 2015. He threw a complete game shutout on his first start, Pride Night, and his teammates wore rainbow socks, Fightmaster said.

Peter Fimrite is a San Francisco Chronicle staff writer. Email: pfimrite@sfchronicle.com Twitter: @pfimrite