Tunnicliffe earned his father £10,000 by making his Manchester United debut on Wednesday night.
The 19 year-old, who was on loan at Peterborough last season, replaced Marnick Vermijl after 77 minutes in United's 2-1 win over Newcastle.
His father, Mick, can now cash in a £100 bet that Ryan would represent United, placed when his son was nine and playing junior football in nearby Heywood.
Bookmakers William Hill also took a bet for the same amount at odds of 350-1 that the youngster would play for his country.
"We will obviously be paying close attention to the progress of Ryan's career in the future," William Hill spokesman Graham Sharpe said in a statement.
"The last time a bet of this nature cost us £10,000 was when Chris Kirkland made his debut in goal for England, also landing a £100 bet for his father," he told the Telegraph.