Ramon Calliste was released by Manchester United in the summer and, to the surprise of many, was given a second chance of making the Premiership grade by the European champions.
And although the 19-year-old did not score in the wind and rain-swept European Championship qualifier, his performance was the key to Wales' victory.
Flynn, who insists Calliste was even better last Friday in the 4-0 defeat in Germany, said of the Cardiff-born striker: "Ramon did very well in Germany against a very good side, and now he has played equally as well in this one. That's two games on the trot now for us in which he has performed at a very high level.
"He didn't get a goal but he produced a superb piece of magic on the line to set up the third and he could easily have had two or three.
"I have certainly been pleased with both of his performances this past few days. He was playing on his own up front but gave them a lot of problems.
"He is still only 19 and he has another two years with us. He's been at Manchester United and now at Liverpool, where he has raw talent that they are clearly working on.
"It is a great opportunity there for him and he is now producing good team play rather than just individual talent. He has pace, control and movement and the team play he is getting into his game hits the nail on the head as to why he has improved."
Calliste caused Azerbaijan constant problems with his movement and pace, with Mark Pritchard, Mark Birchall and Peter Gilbert scoring the second-half goals.
Flynn had a side packed with teenagers - including three 17-year-olds - and was delighted with the all-round display. He said: "Seeing so many of the youngsters out there gives me plenty of confidence for the future.
"We are only losing four of these lads because they are too old - Lee Worgan, Lee Beevers, Peter Gilbert and Anthony Pulis - so there is plenty still to work with.
"We had three 17-year-olds on the pitch and they all played really well. People forget how young some of them are, playing in a difficult competition against much older boys.
"Certainly the two 17-year-olds who made their debuts didn't let anyone down. Curtis McDonald and Shaun MacDonald really impressed me.
"They are both good prospects. Curtis found himself being heavily marked because of his pace, but he has earned his call-up to the under-21s and he took his chance very well. He has a great left foot and good temperament, and he looks like he wants to learn.
"We don't just give caps out for the sake of it even if we have used a lot of players this past year. They all have been worthy of their first caps."Reuse content