Serbia scored two minutes from the end of extra time to beat Brazil 2-1 and win the Under-20 World Cup.
Nemanja Maksimovic finished a counter attack to seal Serbia's first football title as an independent nation.
Stanisa Mandic had opened the scoring in the 70th minute in Auckland, New Zealand, before Manchester United midfielder Andreas Pereira equalised for Brazil with a fine solo goal.
"They can get to the top of the world," said Serbia coach Veljko Paunovic.
"I can tell you in this generation there is a lot of good players that in the next 10 years will play in the best games in the world."
"This is the time for this generation to grow up and say farewell to youth football and this is the best way to do it.
"They have to focus on the next 10 years."