After a seven-year wait - and a dramatic final round - Atletico Madrid have won the Spanish La Liga title for the 11th time.
Fans and players later celebrated together outside the stadium in Valladolid, with more supporters rejoicing in Madrid.
Atletico came from behind to defeat Valladolid 2-1 on Saturday to hold off Real Madrid, finishing two points ahead of their city rivals after almost losing a lead they had held since the ninth round.
Luis Suarez, who was let go by Barcelona against his wishes last season, scored the winner in Valladolid for Atletico - who won their first league title since 2014 in a wild finish that had plenty of twists with the two remaining title contenders playing at the same time.
Real couldn't repeat as champions despite rallying to defeat Villarreal 2-1 at home and giving Atletico a very late scare.
Suarez's goal came as redemption in what he called his "toughest year."
He was key for Atletico throughout the season after practically being handed to them by Barcelona.
"This has been a hard season for the situation I had to go through, starting the season the way it did, being disrespected (by Barcelona) and having Atletico open its doors to me," an emotional Suarez said.
"I will always be thankful to this great club for that."
The results left Atletico top at the end of the 38-round season, adding to the title Simeone led them to in 2014.
The one before that came in 1996 when Simeone still played for them.
As players chanted and celebrated on the field, several hundred Atletico fans held their own celebrations outside the Jose Zorrilla Stadium in Valladolid.
Some players later joined them on their way to the team bus, sharing hugs and chanting together, many without masks despite the coronavirus.
The trophy will be presented to the club on Monday.
"For Atletico to win the title this season, it's different
"It was a difficult year, just like our own history. This was one of the best years for Atletico to be the champion."
After embracing his family, Simeone jumped on the team bus as his players were celebrating and singing "We Are the Champions."
Barcelona were out of contention entering the final round and closed their season with a 1-0 win at last-place Eibar without Lionel Messi, who was allowed to start his vacation early.
Real Sociedad secured fifth place and a Europa League spot with a 1-0 win at Osasuna.
Sixth-place Real Betis won 3-2 at Celta Vigo and also guaranteed a spot in European competitions.
Seventh-place Villarreal will play in Wednesday's Europa League final against Manchester United and can secure a spot in the Champions League if they beat the Premier League giants.
Valladolid and Huesca, who drew 0-0 with Valencia, joined Eibar as the three relegated teams for next season.
Elche escaped the drop on Saturday by beating Athletic Bilbao 2-0 at home.