When Marblehead firefighter Matthew Christensen found out that Salem's new Festivus 5K Roadrace would benefit the Autism Society, he decided to sign up.

Christensen's son, Mac, was diagnosed with autism this past summer and running a road race in his honor, he thought, would be a fun way to support a worthy cause that is close to his heart.

So, in the hopes of signing up a few more local runners, Christensen quickly put together a Facebook page aimed at assembling a team to race in honor of Mac.

The response he received far exceeded his expectations and could certainly be considered a "festivus miracle".

"I got such a flow of support back, I was so surprised," Christiensen said. "We competed with a team of 15 runners, ranging from an Olympic athlete to people who have never run before in their lives."

Yes, that's right, running on Mac's team Sunday morning was Marblehead's very own Olympic gold-medal winner Kayla Harrison.

"My son Mac was waiting for everyone at the finish line to congratulate everyone as they finished," Christensen said, adding, "this means a lot to us, because our son was just diagnosed."

Although Frank Costanza's Festivus is far from a heart-warming holiday - this is one of those local stories that is sure to lift your spirits this holiday season.