Serbia head coach Dragan Stojkovic insisted there is no limit to what the country can achieve after they qualified for the 2022 World Cup in dramatic fashion.
Aleksandar Mitrovic scored in the 90th minute to break Portugal's hearts as Serbia reached next year's showpiece tournament in Qatar thanks to a last-gasp 2-1 victory in Group A on Sunday.
Portugal only required a draw to earn automatic qualification and Cristiano Ronaldo's men were on track after Renato Sanches and Dusan Tadic traded first-half goals in Lisbon.
However, Serbia dominated and were rewarded when substitute Mitrovic headed home late as Portugal were relegated to the play-offs.
"We have no limit, we will analyse everything after this, and we did everything we did perfectly," Stojkovic said post-game.
"We showed in the end that we are better. We have the potential for much bigger things."
Serbia failed to qualify for Euro 2020 following a disappointing play-off defeat to Scotland.
Mitrovic – Serbia's all-time leading scorer – said: "I don't know what to say. I would cry and laugh at the same time.
"Great victory, we came to Portugal to play football, to win. We were better, outplayed the opponent and deservedly celebrated."
Serbia captain Tadic, who equalised in the 33rd minute to cancel out Sanches' early opener, praised the impact of Stojkovic.
Stojkovic was appointed in March, replacing under-fire boss Mladen Krstajic.
"There are a lot of emotions at the moment and everyone is very happy and satisfied," Tadic added. "Since [Stojkovic] came, I think that a smile has returned and that we are playing beautiful football, which we showed today.
"We showed that we can come to Portugal to dominate and win. I think that everyone who wears this coat of arms and who is a citizen of this country should be very happy and proud."
"Serbia should go to the World and European Championships continuously," Tadic said. "I hope that [Stojkovic] will stay for a long time and that Serbia will go to big competitions all the time."