Diego Simeone hailed one of the most important days in the history of Atletico Madrid, while Gerardo Martino bid farewell to Barcelona after a tense title decider went Atletico's way at the Nou Camp.
Diego Godin's header early in the second half cancelled out Alexis Sanchez's 34th minute wonder strike, and a 1-1 draw saw Atletico hang on to their three-point advantage at the top of the table.
And while Atletico were celebrating on the pitch, the players tossing Simeone in the air, Martino was down the tunnel and saying his farewells.
"In agreement with the club I am no longer the coach," Martino said.
"I deeply regret not having achieved the goals that this club has always been set and achieved.
"These are great players. My greatest gratitude goes to the players. They have made me proud."
Barca's sporting director Andoni Zubizarreta said: "We are grateful to 'Tata'. This has been a tough season."
Martino had been widely expected to leave, win or lose, with speculation only increasing after the favourite to replace him, Luis Enrique, announced his departure from Celta Vigo on Friday afternoon.
Martino took over at Barca last summer after the late Tito Vilanova was forced to resign with health problems.
A 7-0 win in his first match in charge, against Levante, led to great hopes but Barca faltered in the league after the turn of the year and fans grew unhappy with his playing style.
Although they went into the final day still in the hunt, the general impression was that Martino had underperformed, albeit in difficult circumstances following the emotional outpouring which followed Vilanova's death in April.
Whoever his replacement may be, he will face a difficult summer.
Although Barca will be allowed to sign players after their transfer ban was lifted on appeal, they must act quickly to replace departed goalkeeper Victor Valdes and long-time captain Carles Puyol, as well as providing cover for an ageing squad with the possiblity of that one-year transfer ban being reimposed.
Martino shuffled off stage as Simeone was gathering himself following exuberant celebrations before holding his own press conference.
Asked about the key to their success, he said: "It was the work-rate, which was never negotiable. We always aimed to have no debt to anyone but ourselves. I think the team always knew what was possible and I think today is sure to be one of the most important days in the history of the club. To leave Barcelona as champions, there is only joy."
Amid the celebrations, there were only a few details of the injuries suffered early in the first half by key men Diego Costa and Arda Turan, leaving both men doubtful for next weekend's Champions League final against Real Madrid.
The club said Costa had suffered a recurrence of his hamstring injury, while Turan had a pelvic injury. There was no word on their status for next week at this stage.
"It was a very hard game," Atletico's on-loan goalkeeper Thibaut Courtois told Sky Sports 1. "I think not a lot of people gave us a chance after last week's draw because Barca just had to win at home and they were really ready for this game.
"After 20 minutes we lost two important players and we went 1-0 behind, but in the second half you saw how we came back. We had to suffer but we suffered and we won.
"This is the story of Atletico Madrid. For so many years Madrid and Barca had all the money, they buy a lot of good players but we had to find another way. We had good players, not the best but we worked harder, suffered in training and had good tactics. You can achieve good things.
"The supporters of Atletico have had difficult years but now they can have some great years and hopefully next week we can give them another trophy."