Barcelona were made to wait for a first piece of silverware under Pep Guardiola as they let a two-goal lead slip at home to Villarreal in the Primera Liga this evening.
Barca had all but wrapped up the title following last weekend's incredible 6-2 win at Real Madrid, a which result saw the Catalans move seven points clear of their fierce rivals with just four games remaining.
And Madrid's 3-0 defeat at Valencia last night meant Guardiola's side could seal their first trophy of what has been an amazing season today.
Seydou Keita's deflected effort gave Barca an early lead, and although Joseba Llorente equalised 10 minutes later, the home side took a two-goal lead in at the break thanks to strikes from Samuel Eto'o and Dani Alves.
And they were cruising in the second half until Eric Abidal was dismissed for the second time in five days with 14 minutes left.
Mati Fernandez converted the resulting spot-kick and Llorente crashed home a dramatic late equaliser to silence an expectant home crowd deep into injury time.
There was a carnival atmosphere inside a packed Nou Camp as Barca set out to win their first piece of silverware this season.
The Catalans face Athletic Bilbao in the final of the Copa del Rey on Wednesday night, but Guardiola named his strongest available side for this match.
Injured duo Thierry Henry and Rafa Marquez were the only players missing from the team's first-choice XI.
But Barcelona lacked their usual intensity in the opening minutes.
Tough matches against Madrid and Chelsea (twice) in the last 10 days appeared to have taken their toll, although Samuel Eto'o almost gave the home side the lead after just six minutes.
The Cameroon striker should have done better with his close-range effort, but Barca did take the lead five minutes later, when Keita's angled drive took a deflection off Gonzalo Rodriguez and looped over Diego Lopez into the back of the net.
The hosts looked happy to sit on their lead after that, but they paid for it 10 minutes later as Villarreal equalised.
Ariel Ibagaza sliced open the Barcelona defence with an intelligent pass to Giuseppe Rossi and the Italy striker squared for the unmarked Llorente, who slid home from close range with Victor Valdes beaten.
And the home side almost paid even more dearly four minutes later, when Rossi looked certain to head home a second Villarreal goal, but Valdes produced a wonderful reaction save to push the striker's header against the post and away from danger.
Things were starting to look more difficult for Barcelona now, but the Catalans retook the lead with a well-worked goal after 36 minutes.
Lionel Messi fed Andres Iniesta from a free-kick and the Spain midfielder somehow managed to beat Gonzalo and set up Eto'o for an easy finish after he had slipped over and recovered his footing.
Iniesta received applause and acclaim from the crowd at the start of the match following his crucial injury-time strike at Chelsea on Wednesday night, which saw Barca progress to the final of the Champions League.
And the midfielder had proved the inspiration once again as Barcelona retook control.
The home side then went two ahead just before the break, when Alves crashed a stunning free-kick past Diego Lopez and into the top right-hand corner.
The Catalans continued to dominate after the break and Xavi had two strikes ruled out for offside as the hosts threatened to rack up another huge score.
But Villarreal were given a lifeline with 14 minutes left, when Abidal pushed over Nihat Kahveci in the area and the referee awarded a penalty to the visitors.
Fernandez kept his cool to fire home the spot-kick amid loud jeers from the home side.
And Barca now had to negotiate the remaining minutes with 10 men after Abidal was sent off.
The France full-back also saw red in last week's semi-final second leg at Chelsea and will now be suspended for both the final of the Copa del Rey on Wednesday and the Champions League showpiece in Rome later this month - unless UEFA show leniency.
Barcelona suffered some nervy moments in the last 10 minutes, but looked to have done enough as the game went into added time.
But deep into injury time, Llorente pounced on a loose ball in the area, side-stepped Valdes and crashed a neat finish in at the near post to silence a Nou Camp crowd who had come to party.
Barca would have been disappointed, but the Catalans are eight points clear of second-placed Madrid with three games left and a draw at Mallorca next weekend will be enough to seal the league title.
Villarreal's point meant they returned to the top six, meanwhile.
Earlier, two goals from Esteban Granero helped drag Getafe away from the relegation places with a 3-0 home win over direct rivals Osasuna, who played most of the match with 10 men.
There was no change in the bottom three after Sporting Gijon and Recreativo Huelva lost and bottom club Numancia drew.
In Sunday's late game Atletico Madrid launched an incredible fightback from 2-0 down against Espanyol to win 3-2 in stoppage time.
Madrid's Luis Perea was sent off on the half hour for a vicious elbow on Francisco Chica before a penalty from Nene and a second from Daniel Jarque put the visitors in the driving seat at the interval.
But a Diego Forlan pearler, followed by a tap in from Sergio Aguero pulled the home side level before Forlan slotted from inside the area in the third minute of added on time to seal a memorable win.