Primera Division holders Real Madrid began the new campaign with a 1-1 draw against Valencia at the Bernabeu after Jonas cancelled out Gonzalo Higuain's early strike.
Los Che, who finished third last season, were well worthy of a point and should have had three but Roberto Soldado's second-half strike was wrongfully ruled out for offside.
The champions made a bright start and after both Cristiano Ronaldo and Angel Di Maria came close early on, Higuain gave the home side the lead with just 10 minutes on the clock.
A wonderful ball over the top of the Valencia backline from Di Maria found the Argentina striker, who, after being denied twice by goalkeeper Diego Alves, thundered a powerful effort into the top right hand corner from inside the area.
Against the run of play Valencia levelled four minutes before the break when Tino Costa's wonderfully whipped free-kick from the right was met by Jonas, who headed home.The Brazilian out-jumped Xabi Alonso, Pepe and Iker Casillas, with the latter two clashing heads.
The home side were let off the hook when early in the second half a through ball inside his own half by Costa found an unmarked Roberto Soldado. The striker ran through the middle unchallenged before rounding Casillas and sliding the ball in the net only for play to be brought back for offside, although replays showed the 27-year-old was onside when the ball was played.
David Villa scored in his first competitive appearance this year and Lionel Messi netted a brace as Barcelona claimed a 5-1 victory over Real Sociedad in new coach Tito Vilanova's league debut in the Nou Camp hotseat .
Villa, who missed the second half of last season and Euro 2012 after breaking his leg in December, netted after appearing as a late substitute to complete the win as Barca showed it was business as usual despite this summer's departure of record-breaking coach Pep Guardiola.
Earlier, during a frenetic start which saw four goals scored in the opening 16 minutes, Barca charged into a 3-1 lead with Carles Puyol - who also missed Spain's triumphant Euro 2012 campaign through injury - notching the first. Sociedad briefly drew level when Gonzalo Castro netted but Messi then struck twice in five minutes to put the home side two goals clear.
Pedro Rodriguez then added a fourth before the break before Villa climbed off the bench to also get his name on the scoresheet.
Real Betis recovered from squandering a 3-0 half-time lead to seal all three points in a 5-3 victory over Athletic Bilbao at San Mames thanks to two goals from Jorge Molina and others from Ruben Castro, Benat Extebarria and Alex Pozuelo.
The visitors had flown into a 3-0 lead after just half an hour thanks to calm finishes from Castro and Molina were followed up by a wonderful strike by Benat. But it was Athletic who stormed out of the traps after half-time when Oscar de Marcos reduced the arrears within 60 seconds of the restart.
Mikel San Jose then twice headed home from corners to bring the Basque side level but Betis were back in front four minutes later as substitutes Jose Canas and Pozuelo combined to allow the latter to slot home.
And with the Athletic defence all at sea, another fine counter-attack from the visitors saw Jonathan Pereira release Molina to seal the points with a delicate chip over Gorka Iraizoz.
First-half goals from Nabil El Zhar and Arda Turan ensured the points were shared as Levante and Atletico Madrid kicked off their campaigns with a 1-1 draw at the Ciutat de Valencia.
The hosts struck first when El Zhar stroked home from the edge of the area after just five minutes but brought Atleti level 15 minutes later with a stunning strike from distance that gave Gustavo Munua no chance.
The visitors then went on to dominate possession but lacked a cutting edge and it was Levante who came closest to a winner when Vicente Iborra's long-range effort came back off the top of the bar.
Tomer Hemed scored at either end of the match to earn Mallorca a season-opening 2-1 win over Espanyol.
The Israel international was on the spot after two minutes and then pounced on a stray ball with five remaining to render Mubarak Wakaso's equaliser worthless.
His winner came after Michael Pereira`s drive had come back off the bar, with the 25-year-old rewarded for showing better reactions than the visiting defence.