Champions Barcelona came through a gruelling La Liga test at a rainswept San Mames on Sunday, beating Athletic Bilbao 1-0 thanks to Ivan Rakitic's first-half header.
Barcelona's Lionel Messi was at the heart of another devastating attacking show.
Real Madrid were dumped out of the Copa del Rey at the quarter-final stage on Thursday after losing 4-3 at home to Real Sociedad, while record 30-times winners Barcelona were sent crashing out of the Copa del Rey in a 1-0 defeat at Athletic Bilbao.
Holders Barcelona produced a second-half blitz to come from behind and beat Athletic Bilbao 3-1 to book a place in the King's Cup semi-finals after Atletico Madrid crashed out in a shock 3-2 defeat by Celta Vigo.
Real Madrid took full advantage of Barcelona's shock defeat at Real Valladolid with a 3-0 home win over 10-man Levante on Sunday that put Carlo Ancelotti's in-form side three points clear at the top of La Liga.
Vietto slotted the ball home with seven minutes to go after Karim Benzema had given visitors Real the lead early on.
Lionel Messi scored one penalty and missed another as his double helped Barcelona sweep Levante aside in the second half in a 4-1 victory on Sunday to maintain their perfect La Liga start.
The shadow of their disappointing 2014 World Cup campaign still hangs over Spain as they prepare to defend their European Championship crown in France next month, according to coach Vicente del Bosque.
Red Star, who won the European Cup in 1991 and reached the latter stages the following season, finished second in Group H behind Arsenal who crushed BATE Borisov 6-0.
Manchester United's woes deepened as stunning goals by Moussa Sow and Jeremain Lens gave Fenerbahce a 2-1 Europa League win on Thursday that left Jose Mourinho's side facing a battle to reach the knockout stages.
Barca overcome solid Bilbao challenge to scrape through 1-0.
Real Madrid brushed off the absence of Cristiano Ronaldo and Gareth Bale to beat Espanyol 2-0 away and maintain their 100 per cent start to the league season while matching the La Liga record of 16 consecutive victories.
An impudent individual goal from Philippe Coutinho steered Liverpool comfortably into the quarter-finals of the Europa League on Thursday after a 1-1 draw at bitter rivals Manchester United completed a 3-1 aggregate win.
Atletico Madrid took advantage of Barcelona's slip-up to go top of La Liga with a 4-0 victory over Real Sociedad as Real Madrid drew 1-1 at Athletic Bilbao and Cristiano Ronaldo was sent off on Sunday.
Liverpool manager Juergen Klopp enjoyed a satisfying return to Borussia Dortmund as his new side frustrated his former charges and claimed a valuable away goal to draw 1-1 in their Europa League quarter-final, first leg on Thursday.
Arsenal qualified for a 17th successive season with a nervy 1-0 win at home to Besiktas and Malmo made it for the first time with a 3-0 win over Salzburg, whose participation ended in the qualifiers for the ninth time in a row.
Liverpool added another fairytale comeback to the history books as they fought back from 3-1 down against Borussia Dortmund to reach the Europa League semi-finals after Dejan Lovren's towering stoppage-time header secured a 4-3 win on Thursday.
Atletico Madrid have a chance to pile more King's Cup misery on neighbours Real after eliminating Athletic Bilbao on Wednesday to set up a last-four clash against the bitter city rivals they beat in last year's final.
News of all that's transpired on and off the football field
Real Madrid lifted the FIFA Club World Cup for a record fourth time on Saturday after thrashing local side Al Ain 4-1 in the final in Abu Dhabi with the help of impressive distance strikes in either half from midfielders Luka Modric and Marcos Llorente.