For Delilah Cassidy, her knight in shining armor arrived in a gray T-shirt while carrying a credit card.

The 22-year-old recent college graduate was at Los Angeles International Airport, trying to board a plane headed home. But American Airlines said her carry-on bag was too big and she needed to pay a $50 fee to get it on board.

The agent wasn't allowed to take cash and Cassidy's credit cart was declined because she had just returned from Europe and her bank was not aware she was back in the country, she said.

She was tired and frustrated and just wanted to go home. 

Up stepped a man she had never seen before. "I got this," he said and handed over his card. He paid her luggage fee and walked onto the plane. 

"I was overwhelmed with emotion and happiness," she told InsideEdition.com. "I started sobbing. I broke down crying."

When she boarded, she saw him seated in first class and tried to pay him with cash. He wouldn't take it. "You don't have to pay me," he told her. "Just pay it forward." And then she gave him a big hug. 

She was embracing Arizona Cardinals tight end Jermaine Gresham, she found out later. 

"What I hope is that it inspires other people to commit random acts of kindness like he did," she said. "To do good just for the sake of doing good."

 After their flight landed in Phoenix, she hooked up with Gresham again and grabbed a selfie with him.

 American Airlines also weighed in after her tweets went viral.

Some of Gresham's fellow players chimed in as well, saying it was no surprise because Gresham is just that kind of man.

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