Thibaut Courtois spoke of his pride at Atletico Madrid's achievements after a 1-1 draw with Barcelona saw them claim the La Liga title.
Diego Simeone's side only needed a point to lift the trophy but a first-half strike from Alexis Sanchez put the hosts in front after both Diego Costa and Arda Turan had limped off with injuries that could affect Champions League final preparations.
Atletico came out from the break full of intent with David Villa hitting the post before Diego Godin rose to emphatically head the crucial goal beyond Jose Manuel Pinto to seal their tenth title.
It was the first time they had lifted the La Liga trophy in 18 years and Courtois, who is due to return to Chelsea this summer following his loan spell, said the victory felt even better because of their underdog status.
"It was a very hard game. Nobody gave a chance to us because after last week, we thought that Barca just had to win against us," he told Sky Sports.
"They were really ready for this game and after 20 minutes we lost two important players for us, but the players who came in did good jobs.
"We went 1-0 behind and second half, the way we came back was great. Then we had to suffer. We suffered and we won."
Atletico will look to add to the trophy when they take on Real Madrid in the Champions League final and Courtois says they have shown great spirit to get where they have this season.
"This is the story of Atletico Madrid. In all the year with Madrid and Barca with all the money they have, they can buy a lot of good players and we have to find another way," he said.
"We have good players but not the best. By working hard and suffering, have good tactics and a good trainer, you can achieve good things.
"It always has been like that. The supporters of Atletico have had difficult years but now there's some great years for them and hopefully next week we can give them another trophy.
"Naturally, if you lose two players and they make it 1-0 it's hard for the team and I think half-time came at a good moment."
Courtois also hailed the half-time team-talk from manager Diego Simeone as they started the second half at a blistering pace with Godin scoring just four minutes after the interval.
"Simeone said 'we are better, we are better but we just missed some details, we have to believe and we are there to do it'," said Courtois.
"I think the first 10 minutes of the second half were right - when we scored - but in the last 30 it was unbelievable. We had to run behind every ball and it was really hard."