Former Middlesbrough midfielder Gaizka Mendieta has credited manager and countryman Aitor Karanka for ending the club's seven-year exile from the Premier League.
For the first time since 2008-09, Middlesbrough are back in England's top flight after Karanka and Co. finished second in the Championship last season.
After losing a heartbreaking play-off to Norwich City in 2014-15, there were fears Middlesbrough's promotion chances might have faded but 12 months on - and with Karanka at the helm - they were not to be denied a runners-up finish behind Burnley.
A former pupil of Jose Mourinho's at Real Madrid, Karanka has played a key role at the Riverside Stadium since arriving in 2013 and Mendieta - who spent five years at Middlesbrough winning the 2004 League Cup - heaped praise on the 42-year-old Spaniard.
"It's fantastic. After too long, and after the season before nearly touching it and losing the final, it shows how well Aitor has done with the club," Mendieta told Omnisport.
"So happy for the fans, for the club, the players, for Aitor, for everyone involved in the city. It's massive.
"It goes beyond football, because people are so attached to the club and the football. It's unbelievable."
Karanka's impact at Middlesbrough has been apparent in the off-season, highlighted by the signings of former Barcelona and Manchester United goalkeeper Victor Valdes and Spanish defender Antonio Barragan from Valencia.
Middlesbrough have also signed Danish midfielder Viktor Fischer, Bernardo and Marten de Roon.
Ex-Spain international Mendieta added: "Aitor has been key. Obviously helped and supported by the club and getting the players he asked for.
"He has proven that he is right. He achieved what he believed in.
"It's not easy when it's kind of your first proper job in terms of a club, having only coached the academies with the Spanish federations. Obviously three years with Mourinho is like a proper master, an advanced course.
"Slowly, slowly he has built his side and it's full credit to him and the players."
Middlesbrough move back into the Premier League at a time when most clubs are taking heart from surprise champions Leicester City.
Leicester defied the odds last term, upstaging Manchester City, Arsenal, Tottenham, Manchester United and Chelsea to lift the trophy in one of the greatest sporting achievements.
But when asked if newcomers Middlesbrough - who open the season at home to Stoke City on August 13 - should be inspired by Leicester, Mendieta warned: "I don't think they should. I think that would be wrong.
"Leicester never thought they could win the league, that's why they probably won it. Their plan was to stay and then all of a sudden, Manchester United, City and Chelsea all kind of failed to the weight of expectations. Then there were Leicester being consistent and playing great football.
"Leicester were never afraid to win anything, which obviously put them where they are. When you win a league, the best team wins it and Leicester did. But they never planned the season to win it, not even Europe, they only though about surviving.
"Next season will be about stabilising and staying in the Premier League for as long as they can. Any further than that, it would be wrong. If any of the players in those teams start thinking they can win it, then you maybe start the season on the wrong foot because it's very unlikely that it will happen again."