Barcelona capped their title celebrations with a 2-1 comeback win at Atletico Madrid that was only soured by an injury to Lionel Messi.
Barca were confirmed as champions on Saturday night when Real Madrid could only draw at Espanyol, but initially looked set to mark the occasion with defeat as they trailed to Radamel Falcao's opener when Messi limped off on 67 minutes.
But by the time their talisman had reappeared, changed and showered, on the touchline Barca had snatched away victory.
Alexis Sanchez equalised on 72 minutes, following a one-two with Cesc Fabregas, before Gabi awkwardly turned a David Villa shot into his own net nine minutes from the end.
The final whistle drew some title celebrations from the Barca players in front of the travelling support at the Vicente Calderon.
It had been win or bust for Madrid with only a victory sufficient to keep the title race alive for another 24 hours.
Given Mourinho's side came into the match with nine wins and a draw in their last 10 games, anything other than three points for Real seemed unlikely.
However, they were disjointed and off the pace in the first half which was dominated by Espanyol, who were unfortunate to only have a one-goal lead courtesy of Christian Stuani's 23rd-minute strike.
Hector Moreno incorrectly had a goal disallowed as Real appeared to have one eye on next Friday's Copa del Rey final against Atletico Madrid.
However, the introduction of Cristiano Ronaldo was followed moments later by Gonzalo Higuain's 58th-minute equaliser.
Espanyol were reduced to 10 men in injury-time when Victor Sanchez was given his second yellow card after following through on Higuain but Ronaldo sent the resulting free-kick high and wide.
It was a much-improved second-half performance from Madrid but it was not enough and Barcelona wrested back the title without even playing.
Malaga and Sevilla both passed up opportunities to gain ground in their respective campaigns to qualify for Europe by playing out a goalless draw at La Rosaleda.
The two sides were evenly matched and although the visitors created marginally the better chances, a draw was not an unfair result in the end.
The result all put paid to Malaga's already slim hopes of finishing in the top four, as they are five points behind Valencia with one game less to play.
Sevilla remained eighthth in the Primera Division table, moving one point ahead of Getafe, but they have still not won away from home since September.
All the day's other games had implications at the other end of the table.
Athletic Bilbao took a giant step towards sealing their Primera Division status after overcoming nine-man Real Mallorca 2-1 at San Mames.
Aritz Aduriz gave the hosts an early lead but then missed a penalty after Andreu Fontas was sent off on 25 minutes.
Fernando Llorente doubled the advantage late in the second half but Mallorca forward Giovani Dos Santos made for an exciting finish by netting a superb goal two minutes later.
However, Mallorca's hopes of snatching a late equaliser were struck a blow in injury time when Ximo Navarro was also sent off for a second booking and Athletic were able to hold on.
Alejandro Arribas struck a second-half winner to earn Osasuna a potentially priceless 1-0 victory over Getafe in their fight to avoid the drop.
Arribas netted 16 minutes from time as Osasuna ended a five-match winless streak with a deserved triumph that moves them four points above third-bottom Deportivo La Coruna, who lost 1-0 at Real Valladolid.
Valladolid guaranteed survival for another season thanks to Javi Guerra's goal three minutes into the second half, taking his team onto 43 points, 11 ahead of the Galicians.
Levante held on to a goalless draw at home to Real Zaragoza despite being reduced to nine men on Friday night.
Midfielder Papakouli Diop was shown a straight red card in the 51st minute for a serious foul on Zaragoza striker Victor Rodriguez before Pedro Lopez was sent off for his second bookable offence in the second minute of injury time.
The result is a much-needed point for Zaragoza, who moved two points clear of the relegation zone following the draw, although it did not live up to their success of the last two weeks which saw them claim wins over Mallorca and Rayo Vallecano.