(CNN) -- Barcelona's week went from bad to worse Saturday.
Three days after it was ousted by Atletico Madrid in the Champions League quarterfinals, Barcelona lost 1-0 at lowly Granada in Spain's La Liga to give Madrid's second club a huge boost in the title race.
Atletico can move four points clear of Barcelona on Sunday, a lead that would render the teams' clash on the final day of the season meaningless -- if Real Madrid is out of contention. Real Madrid replaced Barcelona in second by defeating Almeria 4-0 at home later Saturday but was still without the injured Cristiano Ronaldo.
Real Madrid has 79 points to match Atletico, though trails through head-to-head record and has played a game more.
A combination of inspired goalkeeping by backup Orestis Karnezis and Barcelona misses -- from the likes of Lionel Messi, Neymar and Andres Iniesta -- ensured a night of frustration for Tata Martino's men, who must pick themselves up in time for Wednesday's Copa del Rey final against Real Madrid.
A headline on Barcelona's website Saturday proclaimed, 'The ball didn't want to go in.'
Barcelona registered nearly 30 shots but only one player scored in the game: Yacine Brahimi in the 16th minute.
Granada entered Saturday three points above the relegation zone.
"This is a step backwards," Iniesta told Canal Plus. "Sometimes it's hard to find an explanation when you lose but we just couldn't get the goal.
"Teams like Granada who are playing for their La Liga survival live and die on chances like the one they scored but that was too much punishment for us.
"We tried everything we could to score. It hurts having taken this step backwards with so few matches left."
Surging Atletico visits third-last Getafe on Sunday, hoping to take three more points. Getafe has won once in the league since the end of November.
Dortmund wins the German classic
After winning the league title in record time in late March, Bayern Munich lost its lengthy unbeaten streak, lost in the league for the first time this season and, some would say, struggled to eliminate Manchester United in the Champions League quarterfinals.
Saturday saw another wobble, as Bayern Munich was soundly beaten by Borussia Dortmund 3-0 at home in Germany's biggest club game. For Dortmund, meanwhile, it was the perfect response to exiting in the Champions League this week to Real Madrid.
Henrik Mkhitaryan -- guilty of a miss or two against Real Madrid in the second leg when another Dortmund goal would have forced extra time -- Marco Reus and Jonas Hofmann scored for Dortmund.
Bayern Munich ended the evening with 10 men after Rafinha was given a straight red for striking Mkhitaryan in the face in added time but worse news for Bayern was keeper Manuel Neuer's calf injury. He had to be substituted at halftime.
Bayern and Dortmund are expected to meet again this season, in the German Cup finale.