Trisha Murphy awoke Saturday stressed and barely able to function.

The mother of four works two jobs, as a server at Denny’s and at a nursing home, while going to school to become a nurse.

Her car had been towed that morning, it would be $735 to get it back, and there still was Christmas shopping to do.

Murphy went to work at the diner that afternoon. It was slow. She didn’t think much of the three, grungy-looking men who sat down.

When they finished their half zesty nachos, slow-cooked pot roast and crazy spicy skillet, the man who appeared to be the oldest, insisted Murphy cash him out.

He slid his card and filled out the receipt with a grin splashed across his face. He said, “Merry Christmas dear” before walking out.

Murphy was stunned. He left her a $500 tip.

"I don't know this man's name, but I hope he realizes that he literally saved Christmas for my children and I," Murphy wrote on Facebook. "Yesterday was the day I met Santa!"