"It's truly amazing. I'm very happy to see girls playing," said Massar, 78, of Yuba City, California.
Canada's Emma March and Philadelphia's Mo'ne Davis became the 17th and 18th girls to play in the tournament Frida. It is only the third time in the event's 68-year history that two girls are playing in the same series.
Davis threw a two-hitter to help Philadelphia beat Nashville 4-0. She had eight strikeouts and didn't walk a batter.
Davis, who received a noticeably louder reception than any other player during introductions, said she noticed plenty of girls younger than her in the audience. The applause heightened significantly when Davis struck out the final batter, becoming the first girl to throw a shutout in Little League World Series history.
"It's very unreal. I never thought at the age of 13 I would be a role model," Davis said. "Hopefully, more girls play Little League."
March did not fare as well.
Batting cleanup ahead of her brother — Evan — and playing first base, she went hitless Friday in Canada's 4-3 loss to Mexico.
But March created some excitement when she stepped into the batter's box for the Vancouver, British Columbia, team.
She drove a long fly ball to right field in the fourth inning that the crowd thought might be a home run. However, the hit sailed foul into the stands. Then in the top of the fifth, March stepped to the plate with the bases loaded and Canada down by two runs. After working the count to 2-2, she struck out looking on a pitch that caught the outside corner.
As March trotted back to the dugout, the crowd let the umpire know its opinion of the call as boos reigned down from the stands.
Massar, slated to throw out the first pitch at one of Monday's games, believes more girls will start to play in Little League and beyond. She thinks eventually there will be a woman in Major League Baseball.
Massar played in 1950, leading to a rule barring girls from playing. That rule was overturned in 1974. The self-described "trailblazer" said she celebrates her role in history.
"It's something I'm proud of," she said. "Why not play baseball with the boys?"
Pennsylvania Gov. Tom Corbett was in South Williamsport on Friday and watched Davis' dominating performance.
"There's a lot of pressure on her, and she seems to be handling it very, very well for her age," Corbertt said during the Philadelphia game, adding that the 13-year-old has a nice delivery. "It goes to show you how sports have moved the last 30 or 40 years, and we wouldn't have thought of this 40 or 50 years ago. And today, she's out there pitching, doing a great job and I'm sitting there thinking, 'Is she going to go into professional baseball?' I don't know.
"She's played as well as any kid out there right now."
Also Friday in U.S. play, Pearland, Texas, faced Cumberland, Rhode Island. In the other International game, Japan beat Venezuela 1-0.
The tournament opened with four games Thursday. In the U.S. bracket, Chicago beat Lynnwood, Washington 12-2 in five innings, and Las Vegas topped Rapid City, South Dakota, 12-2, also in five innings. In the International games, Seoul, South Korea, beat Brno, Czech Republic, 10-3, and Humacao, Puerto Rico, topped Perth, Australia, 16-3 in four innings.
PHILADELPHIA 4, NASHVILLE 0
Davis retired the first six batters and needed only 70 pitches. She was hitless in three at-bats.
Jared Sprague-Lott hit a three-run home run in the first inning, and Carter Davis had an RBI sacrifice fly in the sixth.
JAPAN 1, VENEZUELA 0
Takuma Takahashi threw a one-hitter and struck out 14 for Japan.
Takahashi threw 73 pitched in six innings in the opener for the Tokyo team.
Japan scored in the top of the third inning on Suguru Kanamori's single after Taro Hashiguchi reached third on second baseman Greybell Salom's throwing error.
Jorge Cabrera pitched a complete game for the Venezuelan team from Maracaibo.
MEXICO 4, CANADA 3
Juan Garza struck out eight and limited Canada to two in four innings for Guadalupe.
After Canada tied it at 1 in the top of the third, Mexico's Luis Rodriguez hit a two-run homer. The third baseman was 3 for 3, adding a single and a double. Garza added an RBI double in the fourth.