A 4-year-old boy is safe after his attempted kidnapping was thwarted by his quick-thinking big brother and a Good Samaritan who was at the right place at the right time. Christina Pascucci reports for the KTLA 5 News at 10 on Thursday, Feb. 27, 2014.

In Los Angeles last week, a fast-acting taco cook rescued a young boy from a kidnapper.

Last Wednesday, 4-year-old Grady O'Brien was walking home with his 6-year-old brother Brendan and their nanny when a 33-year-old man approached them, claimed he was a CIA spy, punched the nanny in the face, and grabbed Grady, yelling that the boy was his.

Brendan started screaming for help and ran home to get his dad. The nanny, also screaming, tried to chase the attacker.

Jesus Delgado, a cook at nearby T2 Tacos, heard the screams and saw the nanny pointing in the direction of Grady's kidnapper. Delgado ran after him.

He was able to catch up to the kidnapper — and wasn't convinced by the man's suggestion he leave him and the boy alone.

"He told me, 'It's not your problem, man. It's not your problem. Leave me alone with the kid,'" Delgado told NBC LA. "I said, 'This is my problem. This is my problem, because why you take this boy?'"

Delgado, the father of a 4-year-old girl with heart problems, held down the kidnapper until the police arrived to arrest him. While waiting for authorities to arrive, the attacker allegedly took off his clothes and exposed himself, CBS Los Angeles reported.

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The boys' father, Tom O’Brien, said he couldn't thank Delgado enough for saving Grady.

"How can you explain the feeling that you have of gratitude for someone who saved your son's life? It's really an amazing thing that he did," O'Brien told CBS 2.

On Thursday night, O'Brien thanked Delgado in person — and handed him a cheque to help with medical expenses for his daughter.

When the story made headlines, fans of Delgado followed O'Brien's lead and set up a gofundme account to raise money for him and his daughter. So far, they've raised over $21,000.

Delgado's wife thanked everyone for the kind comments and generous donations:

"I just want to take the time to thank everyone for your comments :) I am very proud of him and I am so happy, Blessed and grateful with God for my husbands and Grady's life. Thank God they are both alive and safe. Thank God it was a happy ending. So from Jesus Delgados, me and our daughter... THANK YOU all for your comments and Donations for his herotic (sic) actions," she wrote.

Andron Gazarov has been formally charged with kidnapping, attempted kidnapping, assault by means likely to produce great bodily injury, and indecent exposure. He faces up to 12 years in prison.