volley brought out the best in Molloy with the keeper also making a top save to thwart Mitchell.
Joel Castro Pereira had to rush from his goal to clear but had been largely inactive for the game. The keeper's opposite number Molloy then made an unbelievable stop to parry over Cameron Borthwick-Jackson's close range shot, only for the following corner to leave the plucky Irishmen on their knees.
Andreas Pereira swung the ball across and McBurnie rose highest to power a header against the bar and seemingly over the line with Ruairi Croskery forcing the rebound home in any case.
Mark McGaray was then booked for simulation in time added on after a collision in the box with Joel Castro Pereira with the home fans aggrieved not to win a penalty.
Andreas Pereira was voted player of the tournament after displaying his vast array of skills throughout and the club was also awarded the prize for the most sporting team in the competition, which will no doubt please coach McGuiness.
"It was great for them to get the victory and they're following in some good footsteps," McGuinness told BBC Northern Ireland afterwards.
"We played all amateur teams, rather than professional sides, so you have to be realistic as it's hard to gauge how good they are but they've had a great time and mixed really well. Tyrone made it difficult and their goalkeeper was outstanding - he made three or four fantastic saves.
"In terms of Oliver McBurnie - I think what we will do is pay tribute to Bradford who loaned him to us. He enjoyed his week and will go back there a better player so it's great for everybody."
United: J.Pereira; Reid, Tuanzebe, Borthwick-Jackson, Thompson; Riley (Rashford 46), Willock, A.Pereira, Mitchell; Croskery, McBurnie.