Liverpool handed their fiercest rivals a painful lesson on Thursday with a dominant 2-0 win over Manchester United in the first leg of a Europa League last-16 clash.
Barcelona must appreciate matching the club's record of nine wins and a draw in their first 10 games of a Liga campaign, especially after Real Madrid's defeat at Girona, coach Ernesto Valverde told a news conference on Monday.
Having absorbed the body blow of losing striker Radamel Falcao in the close season, Atletico Madrid have emerged as genuine contenders to break the title stranglehold of Real Madrid and Barcelona.
News of all that's transpired on and off the football field
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.
Barcelona followed up last weekend's 3-1 defeat at Real Madrid with another reverse on Saturday, squandering a host of chances to lose 1-0 at home to Celta Vigo and handing the lead in La Liga to their arch rivals.
Photos from the UEFA Champions League last 16 first leg-matches played on Wednesday
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.
Barcelona and Atletico Madrid led a Spanish Armada into the Champions League last 16 with home wins on Wednesday and in-form Aaron Ramsey steadied Arsenal's boat with a battling win against rocky Borussia Dortmund.
Images from the Champions League round of 16 second leg matches played on Tuesday
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.
Lionel Messi netted the 400th goal of his storied career on Saturday as Barcelona trounced Granada 6-0 to maintain the pace at the top of La Liga.
Real Madrid's early-season woes deepened when they lost 2-1 at home to La Liga champions Atletico Madrid, while substitute Neymar struck twice in Barcelona's 2-0 win against visiting Athletic Bilbao on Saturday.
Andy Murray clinched the Vienna Open title on Sunday with a 5-7, 6-2, 7-5 victory over David Ferrer, one of the Briton's main rivals in the battle to qualify for the ATP World Tour Finals.