Cao's Kitchen in Brockton, Massachusetts, was about to close Tuesday night when an armed teen allegedly grabbed the tip jar off the counter.
"Asked him what he wants to order but he doesn't say nothing, just take the jar of tips," said manager Kelly Ke.
Ke didn't want her face shown, but she showed us how the teen allegedly grabbed the tip jar, pocketed the cash and ran out.
"I just was so nervous I call police," said Ke.
But Ke didn't have to wait for police.
Just outside the door were Jon Bryant and another man, scheduled to clean the kitchen equipment overnight.
Bryant said the teen literally bumped into him trying to get away.
"To have somebody walk right into me and not say 'excuse me,' I said, 'you know what, I'm going after him,'" explained Bryant.
Bryant said as the teen hopped on his bike, he heard Ke yelling "stop, thief!"
"And the only thing I had to do was push him over on his bike," said Bryant. "He got up and he reached for his waist and pulled a knife out."
But what the thief didn't know was that Bryant and his coworker were both retired Marines, both extensively trained in martial arts.
"We put him on the ground and put him in a head lock and an arm lock, until the police came," Bryant said.
And Bryant says he wouldn't hesitate to do it again.
"I would never turn my back on anybody that needed help," Bryant said.
The 17-year-old was arrested and charged with larceny and assault and battery.
The roughly $20 in the tip jar was returned to Cao's Kitchen and its very grateful managers.