A mother said she was "shocked" after a car thief drove off with her newborn as the father stood nearby talking to a friend.
Thomas Moulsdale, 24, suddenly became aware someone had sneaked in the driver's side door and was driving off with his seven-week-old son, Leo, on the back seat.
He tried to open the passenger door shouting that his baby son was in the back but the thief drove on.
The child's mother Louise Waine said: "It made me feel sick. I didn't know what to do ... I was shocked and I just said stop and broke down. I said I don't know where to look ..."
It was a frantic 15 minutes for Mr Moulsdale and his fiancee before the child was found safe and well in the car, which had been left close to a pub.
"Then we got a phone call ... saying they'd found him ... we shot down and I grabbed him out of the seat. I just felt ill. I can't believe someone would do that," she said.
Police are now appealing for any witnesses to the drama - which happened in Moor Road in Orrell, Wigan at 7.35pm on Tuesday - to contact them.
Detective Constable Brendan Greally, from Wigan CID, said: "We can only imagine the distress that the parents of this young baby must have gone through after their son was taken from them in this manner.
"Thankfully, their nightmare was only short-lived after the baby was found safe and well inside the vehicle around 15 minutes later."
Police were told that the baby had been left in the abandoned blue Subaru Impreza on Maine Street, Billinge, by an anonymous caller.
The thief is described as a white man in his 20s, wearing a dark-coloured hat, a dark hooded top and lighter-coloured trousers or tracksuit bottoms.
Anyone with information is urged to call police on 101 or the independent charity Crimestoppers , anonymously, on 0800 555 111.