Real Madrid thrashed Villareal 5-0 while arch-rivals Barcelona beat Athletico Madrid 3-1 on Sunday.
Real were smarting from a surprise 1-1 draw at struggling Elche in their last match and were missing captain Sergio Ramos, who was out with a stomach bug.
The old format was skewed in favour of the bigger clubs, who could rest players for a first leg and swallow defeat before calling on their stars to turn the tie around in the return game.
Villarreal's Argentine playmaker Juan Roman Riquelme is set return to his former club Boca Juniors on loan until the end of the season.
Barcelona crashed out of the Champions League following a 3-0 defeat at Bayern Munich on Wednesday, failing to make it past the group stage of the competition for the first time since the 2000-01 season.
A sloppy Real Madrid were held 0-0 at home to Real Betis on Saturday in a further blow to their hopes of retaining the La Liga title.
Images from La Liga matches played on Saturday.
Atletico Madrid kept pace with leaders Barcelona and restored their five-point lead over third-placed city rivals Real when Diego Costa and David Villa each scored a penalty in a 2-1 win at Granada in La Liga on Thursday.
Cristiano Ronaldo scored twice but had to leave the pitch with his face covered in blood as Real Madrid eased their domestic crisis by hammering Liga strugglers Deportivo La Coruna 7-1 at home on Sunday to reclaim fourth place in the standing
Summary of all that transpired on and off the football field
Real Madrid's talismanic forward Cristiano Ronaldo is set to face Manchester City in Wednesday's Champions League semi-final second leg after coming through training on Monday.
A round-up of weekend action in the main European leagues.
The Barcelona striker wants an all-Spanish Champions League final against Villarreal in Paris on May 17.
United's Ibrahimovic, Roma's Dzeko find the net thrice to give clubs first leg advantage
Real Madrid star striker Cristiano Ronaldo will travel with the team for the first leg of the Champions League semi-final clash against Manchester City after recovering from a thigh injury.
Underdogs Olympique Lyon and Villarreal will attempt to triumph over the Milan teams
Following public comments from La Liga chief Javier Tebas, who said it was "not ideal" for the second El Clasico meeting between Real and Barca last season to be played with the latter having already won the league title, the two sides will face off earlier this campaign.
It has been a long time arriving but Manuel Pellegrini can finally celebrate some meaningful European silverware - 10 years after arriving in Spain as a relative unknown.
World No.1 Serena Williams has held on to her top position in the latest women's tennis rankings issued by the WTA.
Atletico Madrid put last week's painful defeat by Real Madrid behind them with a 3-0 win over Osasuna on Sunday that included two goals in the space of a minute and allowed them to return to the top four in La Liga.
Alexandre Lacazette's free-kick sent Arsenal into the Europa League semi-finals with a comfortable 1-0 win away over Napoli, while Chelsea beat Slavia Prague 4-3 in a roller-coaster game, helped by a Pedro brace.
Former Arsenal and France midfielder Robert Pires, a member of France's 1998 World Cup-winning squad, has announced his retirement from football at the age of 42.
Chelsea's Ruben Loftus-Cheek had a Europa League night to remember by scoring the first hat-trick of his career as the midfielder inspired them to a 3-1 home win over Belarus champions BATE Borisov on Thursday.
The hard-fought win took Zinedine Zidane's side on to 77 points after 34 games, seven clear of second-placed Barca who visit in-form Villarreal later on Sunday.
Karim Benzema struck twice as Real Madrid went to the top of La Liga with a 4-2 win over Villarreal on Saturday while midfielder Verza's double gave Almeria a shock 2-0 victory over Atletico Madrid.
A summary of Saturday's action in Serie A and La Liga.
News of all that's transpired on and off the football field
David Moyes continued his unbeaten start at Real Sociedad when he rested a host of regulars in a 0-0 draw at third-tier Real Oviedo in a King's Cup last-32, first-leg match on Thursday.
Ruben Baraja scored two goals as Valencia rallied to sink regional neighbours Villarreal 4-2 in the Spanish League.
An Aaron Ramsey strike and a Kalidou Koulibaly own goal gave Arsenal a 2-0 victory over Napoli in the first leg of their Europa League quarter-final, while Chelsea beat a stubborn Slavia Prague 1-0.
The weekend was a goal-feast with footballers from all over Europe keeping their names on the scoresheet. Rediff.com brings you the top goal-scorers of the weekend.
Portugal international Goncalo Guedes fired Valencia into the lead in the 35th minute with a thumping shot from inside the area which was too powerful for Madrid goalkeeper Keylor Navas.
Valencia's Paco Alcacer and Dani Parejo both hit doubles in a surprise 5-1 away thrashing of high-flying Celta Vigo in La Liga on Saturday.
Spanish rivals Villarreal and Valencia had to settle for a goalless draw in the first leg of their UEFA Cup semi-final.
Manchester Utd's Fred receives racist abuse after defeat by Liverpool.
Barcelona and Atletico Madrid dropped their first points of the season on Saturday, missing the chance to equal the record for the best-ever La Liga start.
Manuel Pellegrini's record against Pep Guardiola is a sorry one but he gets another chance to finally put one over his tormentor when Manchester City host holders Bayern Munich in the Champions League on Wednesday.
A mesmeric Lionel Messi helped Barcelona to come from behind and beat Sevilla 2-1 in a thrilling encounter on Sunday as the champions kept the pressure on La Liga leaders Real Madrid, who saw off Leganes 3-0 thanks to a double from Gareth Bale.