Barcelona midfielder Andres Iniesta paid tribute to Atletico Madrid after Diego Simeone's side sealed La Liga glory at Camp Nou.
The hosts appeared well placed to pip Atletico by virtue of a superior head-to-head record when Alexis Sanchez's blistering strike gave them a 34th-minute lead.
But Atletico, without key men Diego Costa and Arda Turan because of first-half injuries, flew out of the blocks after the restart and leveled decisively through Diego Godin's header.
Barca could not find the goal it needed to win the league and, after rising to acclaim the new champions, the home supporters whistled and jeered their own players at the end of a trophyless season that looks set to cost coach Gerardo Martino his job.
"Atletico are deserved champions," Iniesta told reporters. "But it's been a disappointing season for us."
Barcelona sporting director Andoni Zubizarreta echoed Iniesta's sentiments when it came to the Madrid outfit but refused to label his own team's efforts as a failure
"Congratulations to Atleti," Zubizaretta told reporters. "It wasn't that Barca failed; we were up against really tough opponents."