At about 2.20pm, Chicken King takeaway in Padholme Road received a call placing an order for delivery to an address in Kesteven Walk.
A short while later, the order was delivered to the address given during the phone call, however a woman answered the door and told the driver she had not ordered any food.
Whilst the driver made a phone call back to the chicken shop to check the details of the order, Simpson and Hilton appeared and demanded the victim hand over money and the food.
Threatening to stab him, the pair took the iPhone from the victim’s hand, searched his pockets and took his wallet, keys and a £5 note, as well as the bag of food, before running into a nearby flat.
The victim, who is in his 20s, flagged down members of the public who called police and surrounded the flat to ensure Simpson and Hilton didn’t leave.
Despite attempting to flee through a window, the pair were arrested and the stolen property was located inside the flat.
DC Tessa Munro said: "The quick action and support given to the victim by the passers by meant we were able to ensure Simpson and Hilton were swiftly arrested and didn’t have time to get rid of any evidence.
"Thankfully the victim wasn’t injured during the robbery, however incidents involving knives can so often have devastating effects on our communities."
Simpson, of Eaglesthorpe in New England, admitted charges of robbery and possession of a bladed article, while Hilton, of St Michael’s Gate in Parnwell, admitted a charge of robbery.
Both men appeared at Peterborough Crown Court on Friday, January 15, where they were each imprisoned for 30 months, Hilton's detention is at a Young Offender Institution.
Anyone with information about someone who carries a knife is urged to report it to police online here.