By Katie Brace

CAMBRIDGE (CBS) – America’s greatest pastime went back in time Thursday night.

“It’s been pretty cool,” said spectator Jake Bartlett.

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The Oldtime Baseball Game took over a Cambridge ball field. Most of the players are on college teams, but on this summer night they wore the flannel baseball uniforms of decades gone by.

One of the so-called old-timers was Red Sox legend Roger Clemens. “I thought I was going to be playing against guys more my age but I see some awfully young, big kids out here,” said Clemens. “It’s for a great cause.”

Roger Clemens pitches at the Oldtime Baseball Game in Cambridge, Aug. 22. (WBZ-TV)

The annual game raises money for charity. This year it was in memory of a man who dedicated his life to baseball. For more than 40 years, John Welch worked at Fenway Park, for many as the security supervisor. He lost his four-year battle with ALS last December.

“Him and Roger they’ve met multiple times, so to be able to face Roger is really cool, cool experience. I know my dad will be behind me trying to help me,” said Welch’s son Johnny.

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The money raised at goes toward Compassionate Care ALS.

Oldtime Baseball Game at St. Peter’s Field in Cambridge (WBZ-TV)

“The hospital is great, but once you get out of there it’s trying to figure out how to rebuild your home and how to survive,” said Welch.

“My dad has ALS,” said seven-year-old JP Pellina.

For JP, watching Johnny Welch at bat and seeing the crowd cheer was the home run.

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“They are caring for everybody that has the disease and they are just good people,” JP said.