Title favourites Real Madrid and Barcelona both slipped to opening day defeats on Sunday as underdogs Deportivo La Coruna and Numancia took the headlines.
Champions Real sorely missed Brazilian Robinho, excluded from the squad due to his insistence on a move to Chelsea, as they fell to a 2-1 defeat against bogey side Depor. The Galicians continue to hold sway over the capital giants who have not won at their Riazor stadium since the 1991/92 season.
Rivals Barca fared little better with Pep Guardiola's first league match in charge ending in an embarassing 1-0 loss to promoted Numancia.
Guardiola, a member of Barca's 1992 European Cup winning team, has the job of wrestling the title from Real but the omens do not look good after an insipid display.
"It was a big slip-up," admitted Guardiola. "We were poor going forward and know we have to improve."
Real also have some room for improvement if their display against Depor is anything to go by. With Wesley Sneijder injured and new signing Rafael van der Vaart suspended coach Bernd Schuster drafted in Argentine Gonzalo Higuain.
Robinho, pining for a move to Chelsea, had been left out of the squad so Arjen Robben provided the width.
After just 90 seconds Depor gave Real a shock when Mista, who failed to cut the grade at Real Madrid as a youngster, hit the crossbar. He then scored, heading home on 26 minutes after some shocking Real defending.
Ruud van Nistelrooy equalised two minutes after the interval but Alberto Lopo restored Depor's lead four minutes later with a glancing header.
Barca were poor travellers last season under Frank Rijkaard and the new manager and season has failed to bring a change in fortune.
Barcelona handed a league debut to Dani Alves - a 29.5 million euro signing from Sevilla in the summer - with Lionel Messi starting in attack after inspiring Argentina to Olympic gold.
Numancia took the lead with Mario rifling home on 12 minutes after Barca's defence failed to deal with a cross from the left.
Barca twice hit the woodwork through Samuel Eto'o and Messi but Numancia held on for a historic win.
After just one game the league now goes on international break until 13/14 September giving Guardiola and Schuster time to ponder their team's shortcomings.
Atletico Madrid top the table after they followed up their impressive midweek qualification for the Champions League with a crushing 4-0 victory over promoted Malaga on Sunday.
Dutch international Johnny Heitinga scored 26 minutes into his league debut and Diego Forlan grabbed a quick fire brace before the interval to leave Malaga down and out. Florent-Sinama Pongolle completed the rout with a debut goal.
"We showed we are a great team today," said Pongolle. "With the quality we have in the team we are going to score goals. "On a personal note it was a double boost as I made my debut and got a goal."
For the first time in their history Atletico fielded a starting XI without any Spanish players - although Argentine Mariano Pernia has dual nationality - but the fans will not care as long as they continue winning.
Last season's runners-up Villarreal were left frustrated as they were pegged back to a 1-1 draw by Osasuna.
Marcos Senna, a revelation for Spain in their UEFA EURO 2008 success, netted on 54 minutes to put Villarreal ahead but Osasuna levelled 15 minutes later.