Then, in 1990, Kennedy merged with Willingboro - the end of a very particular era in New Jersey youth soccer.
But the players never forgot. Most kept playing - some in college, some professionally, some just for fun. They coached for their kids' teams, or their students' teams, or their own over-35 teams. Many stayed in touch with one another. On Facebook this year, a few former players started a debate: In an all-star Willingboro vs. Kennedy match, who would play? Who would win?
As it turned out on Saturday, Kennedy did, 5-1. No one cared much. For the players, from the classes of 1972 to '92, just being on the field was enough.
"Ninety percent of this is seeing people you haven't played with in 30 years," said Mike Randall (Kennedy, Class of 1987), a Willingboro police captain who also coaches the girls' soccer team at nearby Moorestown High School.
On the field, not much had changed: Players hustled for the ball as though it were a night game in the mid-80s and Willingboro had just tied the score. There were a few missteps, a few ice packs applied to a few heads, and one or two nasty falls - in short, a fairly uneventful soccer match.
From the stands, family and friends watched as the alumni raced up and down the field. Some had flown from as far away as Florida and Washington state for the game.
"The rivalry was pretty intense - for every sport it was intense, but soccer was the big one back then," said Audrey Riley, whose brother Phillip Mitchell, a doctor from Denver, played for Kennedy. "I think it's great they can still get together and kick a soccer ball around."
Former Willingboro coach Jack Mulder, who retired in 2007, watched from the sidelines with a handwritten roster on his clipboard.
"It's an unbelievable experience, watching them all grown up," he said. "Whoever organized this - God bless them."
As the game wore on, the rules relaxed. Children ran onto the field and tried to outpace parents. Ducilli and Mulder laced up their cleats and joined the game for a few minutes. On the sidelines, Willingboro players wandered over to the Kennedy bench and caught up between plays.
"I remember a lot of my classmates - they've changed a little bit but they're still the same," said Charles Johnson (Willingboro, Class of 1977), who was captain of Willingboro's first soccer team.
Many said they wished the two teams could have merged sooner.
"If you look at the talent on both teams, they were very good individually," mused Dave Grassie (Kennedy, Class of 1987), a science teacher from Irvington, N.J. "But if we had combined, we would have been dominant nationally."
The final seconds of the game wound down to cheers from both sides. The soccer stars of yesteryear lined up on the field to shake hands and ended up hugging instead. Both teams - about 50 players in all - clustered on the sidelines for a group photo, all smiles.
Still, old rivalries die hard.
"Let's all celebrate Kennedy's first win," a Willingboro player shouted as the cameras flashed.