"I've done it a couple times, and I've advanced to sectionals," Isaacman said, "but this is the first time I've won sectionals."
Isaacman excelled in each event of the competition, but particularly stood out with the bat in his hands -- which he said is his strongest event.
The competition is made up of a timed sprint from second base to home plate, a strike-throwing event, and a distance hitting competition off of a tee.
Isaacman was one of 22 children ages 7-14 who participated in the team championship at Petco Park, after advancing from local and sectional rounds. The eight first-place winners from each division will have their scores compared with the first-place winners from across the country for a chance to attend the 2016 All-Star Game presented by Mastercard at Petco Park.
All 30 Major League teams will host team championships at their ballparks on weekends through the end of June. The top three competitors nationwide from each division age group (7-8, 9-10, 11-12 and 13-14) will advance to the national finals, which will be held before the T-Mobile Home Run Derby on July 11.
"I did a lot of hitting off the tee at fields," Isaacman said. "My dad hosted the locals. He had the pitching [target], so we practiced that a lot, and then the running was just running."
Isaacman's father, Drew, said he was probably more nervous than his son was.
"I had butterflies for him the whole time," he said. "He worked hard at it -- and he's not a win-at-all-costs kind of kid -- but we put a lot of time in, and he expected to do well.
"And he did."
Alyssa Ahinger placed first in the 13-14 softball division after throwing four of six balls for strikes and impressing in the running and hitting components as well.
Ahinger took a slow and steady approach when it came to the strike-throwing event, and it paid off for her as she tied for the most accurate arm of the day.
"It's kind of like, you do it a lot and you're like, 'OK, I just kind of have to get a system,'" she said. "I have a system where I just take a deep breath, step up and throw -- kind of concentrate on it, just one spot."
Ahinger said it was "awesome" to get the chance to play on a big league field and could spot the difference with essentially her first step.
"It's more of a quality field," she said. "Just the dirt feels different -- it's darker. It's nice."
The other winners were Summer Gilliam (7-8 softball), Carmen Sarmiento (9-10 softball), Ensley Uyeda (11-12 softball), A.J. Curry (7-8 baseball), Elias Bosang (9-10 baseball) and Frank Stehly (13-14 baseball).