A couple of hours before the San Francisco Giants and Philadelphia Phillies squared off in their series finale at AT&T Park last weekend, two other “rivals” went at it on a diamond 16 miles away.

It was Congregation Kol Shofar of Tiburon vs. Congregation Rodef Sholom of San Rafael in the first game of what organizers hope grows into a flourishing adult coed Jewish softball league in Marin.

“I had heard about other Jewish leagues in Southern California that had become such a phenomenon, and I thought why not here?” said Aaron Parker, the head of the Kol Shofar team and the man with the big dreams.

The “league” doesn’t have a second game scheduled yet, but the first one certainly showed promise for the future. Kol Shofar’s roster included 21 players, and Rodef Sholom suited up 11, and about 40 fans — family members, friends, congregation staff, one rabbi and even family pets — showed up at Boyle Park in Mill Valley for the 10 a.m. Sunday game.

A Kol Shofar youth group set up a small snack bar, selling peanuts, drinks, sandwiches and (of course) bagels and cream cheese to raise money for a retreat weekend.

In addition to laying the groundwork for a league, Parker, the co-chair of Kol Shofar’s brotherhood, said he was looking for an innovative way for members of his synagogue and Rodef Sholom to meet.

“Starting this league was a perfect opportunity to get Jewish adults, even families, to come together for something fun,” he said.

Although Parker said this is the first time there has been a Jewish softball league in Marin, it is not the first Jewish league in the Bay Area.

In fact, a 10-team Jewish league in the East Bay, featuring teams mainly from synagogues in Contra Costa County, but also from an Oakland synagogue and other Jewish groups, has been active since 1983. The Diablo Valley Tzedekah Softball League concluded its most recent season last month.

Parker said he plans to make contact with the East Bay league in the future. But for now, his focus is on his new endeavor.

For starters, he said the age range of people who turned out for the Kol Shofar team “has truly been motivating.” The youngest player Aug. 7 was 20 and the oldest were in their 60s.

Talk of creating the league began in January, but the first scheduled game got a delayed start due to conflicting schedules.

“It’s been a long time coming, and everyone has held onto the excitement for quite some time,” said Matt Elkins, a member of Rodef Sholom and coach of that synagogue’s squad.

A number of details went into planning the game — hiring an umpire, getting T-shirts, figuring out rules and finding a date and location. And just to keep things safe and friendly, the teams created a no-touch rule at home plate so there wouldn’t be any collisions.

The seven-inning game lasted a little over an hour, and Rodef Sholom, despite having fewer players, came out on top with an 18-9 victory.

“It was a satisfying experience,” said Lisa Michael Hegwer, the only woman who suited up for Rodef Sholom; Kol Shofar had three women who played. “Everyone really came together, bonding over the game, and high-fiving left and right with excitement.”

Parker said that the game was everything he anticipated and more. “I was on a high the whole time,” he said. “The enthusiasm and smiles are endless.”

“We’ve ultimately created our own softball chavaruh,” Elkins added.

The league is hoping to hold its second game later this month or in early September.