Last summer, if someone had told you that La Liga would be won by a team other than Barcelona or Real Madrid, you would’ve laughed them off. You would’ve been within your rights to do so too. After all, no team other than the ‘Big 2’ had won La Liga since Valencia’s triumph in 2004. And it’s not just that. It’s the fact that no one else, more often than not, had even come close. Last season even when Atletico finished third, their highest La Liga position since the last won the title in 1996, with 76 points, they were still 24 points off the champions, Barcelona. This was the smallest gap between first and third since 2009. Barcelona and Real Madrid had dominated La Liga. No other team had finished first and second in the league since 2008. It had become commonplace to refer to the team that came third in La Liga as the champions of the ‘other’ league.

It is for this reason that when Atletico were still in the mix halfway through this season, most critics were certain that Atletico would not be able to keep pace with Barcelona and Real Madrid come the business end of the season. Atletico aren’t used to fighting for the title, they said. They will start dropping points, they said. Most of the talk at that stage was still about where Barcelona and Real Madrid stand relative to each other.

But Atletico persisted. Week after week they delivered. Even when they didn’t play well, they showed that they can get the result. What resulted, on May 17, was one of the most exciting finales ever to a European domestic league. The La Liga title had gone down to the wire in the most fantastic fashion. Not only was the winner be decided on the last day of the league, it was to be done so in the closest thing to a domestic league ‘final’ we are ever likely to witness in a major European league. Barcelona and Atletico, first and second, facing off directly at Camp Nou for the title. The equation couldn’t have been simpler: If Barcelona won the match, they would take the league. If they didn’t, it would be Atletico’s. The fact that the title fight had even got to this stage was ground-breaking for La Liga. What followed made it even more remarkable. During the match, Barcelona took the lead in the first half with a wonderful volley from Alexis Sanchez. To make matters worse for Atletico, they lost two of their leading players, Diego Costa and Arda Turan, to injury before half-time. They were staring down the barrel at half-time. But whatever their manager, Diego Simeone, said during the break worked. Atletico came out fighting in the second half and equalised with a header from centre-back Diego Godin. After that, Barcelona pressed hard for a winner, but Atletico’s defence was as organised and resilient as it had been all season. Atletico held on to the draw making them champions at the full-time whistle, their first La Liga title since 1996. Atletico’s victory might not be the ultimate underdog story but it comes pretty darn close.

If that wasn’t impressive enough, their performance in the Champions League made their season even more special. After eliminating Milan, Barcelona and Chelsea in the knock-out rounds of the Champions League, Atletico booked a date with bitter city rivals Real Madrid in the final on May 24 in Lisbon. Fighting for the league title and the Champions League concurrently at the end of the season can usually be daunting and overwhelming even for the established elite of Europe - the likes of Bayern Munich, Barcelona, Real Madrid. The fact that Atletico have done it in a season when fighting for either of the titles is a new experience for them, is nothing short of amazing. During the final, for most of the match, it seemed like Atletico were on the verge of securing a historic La Liga and Champions League double too, but for a cruel twist of fate. Atletico secured the lead in the 36th minute when Godin scored from a header. For the second time in a week, it was looking like a Godin header would hand Atletico a major title. But in the 93rd minute of the match, with only two minutes left, Sergio Ramos rose to the occasion and scored with a wonderful header from a corner to equalize for Real Madrid and take the match into extra-time. Atletico had already given all they had. There was nothing left in the tank. This was evident at the start of the extra-time. They could only hold on to the draw for so long. In the last 10 minutes of the match, Real scored three times to win a historic 10th European Cup, or as they call it, ‘La Decima’, the tenth. This was a hard blow for Atletico. They had been only moments away from winning the Champions League and putting the perfect cherry on top of their already successful season. And that is a point worth emphasising. For all its glitz and glamour, the Champions League title would’ve only been the cherry. La Liga was always going to be the cake. Like any other tournament with a knock-out format, the Champions League can sometimes be conquered by teams that have generally had an inconsistent season but have managed to have a good cup run. Read Chelsea in 2012. For that reason, beating Barcelona and Real Madrid over the course of 38 matches was always going to be the real achievement.

Atletico have defied all expectations with their performance this season. However, the doubters will still tell you that this season is a one-off; that Atletico have punched far above their weight, that they might have done well this year but they won’t be a threat next season. They have some evidence to back their scepticism too. After all, Atletico did begin the 21st century with relegation to Spain’s ‘Segunda’ (2nd) division. It took them two years to return to La Liga. For the following five seasons their La Liga finishing positions read 11-7-11-10-7. Despite their claims of being the third biggest team in Spain, they had built a reputation of a team that thoroughly entertained but always had a tendency to implode. The Tottenham Hotspurs of Spain if you like. Atletico won the UEFA Europe League in 2010 and 2012, but in each of those respective seasons their La Liga finishes were 9th and 5th respectively. One can add to this the fact that Atletico have had a track record of not being able to hold on to their big name players, strikers particularly. In recent seasons, they have sold Torres to Liverpool, Aguero to City, and Falcao to Monaco. Even now, there are rumours of Diego Costa departing to Chelsea in the summer.

But here’s the thing. Atletico have become so used to such departures, they have learnt how to do deal with them without the team taking a step back. The Falcao sale last summer is case and point. When Falcao departed, there was a lot of pessimism about Atletico’s chances this season. After all, in his two seasons at the club, Falcao had been the focal point of the team. The main man leading the line. There were questions over which big name signing Atletico would go for to fill the hole left by Falcao. Rather than splashing big money, the manager, Diego Simeone, chose to trust Diego Costa, the man who had deputised for Falcao in the previous season. The reputation Costa generally held then was of a brutish striker who used to come on as a sub to ruffle up defenses by throwing his weight around. Sid Lowe once wrote that if Costa took his work home with him "he might goad the dog with a stick, surreptitiously elbow his wife out the way, shrug his shoulders as she lay in a crumpled heap and whisper insults to his children." But that was last season.

When Simeone turned to Costa to lead the line, there was a lot of surprise. Eventually Atletico did end up signing David Villa from Barcelona at a reasonable price to have an additional striking option, but Costa was to be the main man. The effect of Simeone’s belief in Costa has been nothing short of transformational for the Brazilian-born striker.

He has lead the line impressively and scored consistently - Costa finished the season with 27 goals in La Liga, only one behind Messi and four behind Ronaldo. He has surprised many with his nimble footwork, and his contribution to the build-up play. As a result, Costa, previously ignored by Brazil, has been snapped up by Spain, due to his Spanish nationality, and will be leading the line for the World Champions at the World Cup in three weeks’ time in Brazil.

Simeone’s influence doesn’t end just with Costa. This Atletico team has had Simeone’s stamp all over it since he took over as manager in 2011. When he was signed as manager, many viewed it as a romantic appointment. A former player much loved by the fans returning to manage the club, but expectations weren’t too high. However, Simeone quickly went to work and from the early days you could tell he had started moulding the team in his own image. During his playing days, Simeone was an energetic and dogged defensive midfielder. You could use those two words, ‘energetic’ and ‘dogged’, for this Atletico team as well. From the first minute to the last, Atletico’s work rate is remarkable. The defensive line is well-organised, and the midfielders and forwards press intensely, often suffocating teams into losing the ball. They counter rapidly, and even when there isn’t an opportunity to counter, they move the ball around quickly. The players play for each other. They play for Simeone. If you ever see Simeone on the touch line, you’d think he’s playing as well. A more animated football manager, you will not find. And you can tell that the players feed off his energy and intensity on the touchline. Simeone has built a team where each player plays to his potential, and where the team is greater than the sum of its parts. There is something fundamentally different about this Atletico team. There is a confidence and a belief in their own ability. They have been happy to go toe-to-toe with the likes of Barcelona or Real Madrid. This time it’s more permanent.

Atletico’s achievements this season have breathed new life into Spanish football. They’ve broken the duopoly of Barcelona and Real Madrid, making the league more exciting. Granted that Atletico’s budget is still dwarfed by those of Barcelona and Real Madrid, and repeating this season’s performances will be hard next season. In some ways, a strong run next season would be even more impressive that this season. But a grass ceiling has been broken. Barcelona and Real Madrid will no longer ignore Atletico.

They will be anxiously looking over their shoulders. Spanish football has a third force. Atletico are no longer just the ‘other’ team from Madrid. They have arrived. And it’s good news - for Atletico, for Spanish football and for football fans worldwide.