Luis Suarez and Atletico Madrid stars celebrated into the night on Saturday with fans they had not seen all season after their La Liga triumph.
More than 3,000 supporters gathered outside Real Valladolid's Jose Zorilla Stadium as Atletico came from behind to win 2-1 and edge out rivals Real Madrid for the title.
The team then went back to Madrid for more celebrations with thousands of fans gathered outside their Wanda Metropolitano stadium, with flares and partying.
The relief was huge for Atletico players and supporters after the team, who were on top since December but almost threw away a 10-point lead in February.
Manager Diego Simeone paid tribute after the challenges of a season hit by the pandemic.
"It speaks of the club and the team being made of something different," Simeone said.
Atletico found it tough against Valladolid, with Suarez netting the winner after they had gone behind.
"Everyone tells you that suffering is part of Atletico's identity," Suarez said. "I didn't think we'd suffer that much."
It is only the second time in 17 seasons that neither Barcelona nor Real Madrid have won the title, the other being when Atletico clinched La Liga in 2014.