MADRID (AP) -- Even Atletico Madrid cannot deny that Spain is now a league of three.
After winning 1-0 at Real Madrid early in the season, with Diego Costa scoring the winner, Atletico coach Diego Simeone still called it "a league of two." No longer.
Atletico showed the verve of a veteran champion as it rallied to draw 1-1 Saturday at Barcelona to secure its first league title in 18 years, capping one of the most entertaining Spanish league title fights in recent history.
Atletico needed a draw at the Camp Nou and got it to end a duopoly that had seen either Barcelona or Real Madrid crowned domestic champion since Valencia lifted the title a decade ago.
Atletico showed season-long durability despite a thin squad that cost a fraction of its rivals, who counted on the likes of Lionel Messi, Cristiano Ronaldo, Neymar, and Gareth Bale.
And Atletico is not done yet.
Simeone leads his team into the Champions League final against city rival Real later this month, bidding to follow up a 10th domestic title with a first European Cup to cap the greatest season in the club's 111-year history.
Atletico won by relying on the characteristics that have always marked it out: teamwork, discipline and a flare for late dramatics.
"Hard work. Work is not negotiable," said Simeone about the key to its improbable title win.
"We never underestimated anybody, the team always understood that and they performed well and today will be one of the most important dates in Atletico history. To leave Barcelona as champion provides enormous happiness."
Simeone proved to be the difference for Atletico, as the Argentine coach was a player when Atletico won its last league to go with a Copa del Rey title to close the 1995-96 season with an historic double.
There is little indication Simeone's squad cannot complete its date with destiny by lifting Europe's biggest prize in Lisbon on May 24.
Atletico survived a few hiccups to lift the crown and set a club record for points along the way with 90. Barcelona and Madrid finished on 87 each.
The blue-collar club from Madrid's south side picked up from last season's surprise Copa del Rey final triumph against Madrid -- its first derby victory in 14 years -- and never relented as it built off the domestic cup trophy.
It lost the Spanish Super Cup to Barcelona on away-goals but won eight straight league games, including at Madrid, to raise eyebrows.
Atletico rebounded from its first loss with a 23-game unbeaten run in all competitions to take a three-point lead atop the standings that Barcelona had led for most of the first half of the season. But it lost 2-0 at Almeria on that first test to lose the advantage.
Feeling the heat, Atletico was blown out 3-0 at Osasuna for Madrid to take the outright lead. But Atletico followed with a 2-2 draw at home to Madrid to secure the head-to-head advantage against its rival.
Atletico won its next 10 straight wins -- grinding out more than a handful of single-goal wins -- while Madrid faltered after an emotional Champions League semifinal triumph over Bayern Munich.
But Atletico also dipped after beating Chelsea to return to the European Cup final for the first time since 1974 as it failed to pick up a victory in the penultimate round to clinch the title, keeping Barcelona in the hunt despite its own irregular play.
Atletico became the first team since Espanyol in 1939-40 to go unbeaten against Barcelona in six meetings, and Saturday's may be the most memorable.
For Spanish league fans, too -- as the 99,000-capacity Camp Nou's home fans demonstrated with chants of "Atleti" as the visitors celebrated.
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