Sevilla, Valencia and Getafe all lost on Sunday in La Liga, with the three candidates in the race to finish fourth choking in their bid to qualify for the Champions League next season.
Eibar dealt Valencia a significant blow with a 1-0 win at Mestalla, while Girona earned a crucial win in their bid to escape relegation, defeating Sevilla by the same scoreline.
Having seen those two sides fail, Getafe could have earned a crucial win but stumbled to a 2-1 defeat at Real Sociedad.
Rayo Vallecano earned an impressive 1-0 win over Real Madrid thanks to Adrian Embarba's penalty.
Cristian Portu's goal earned Girona their first victory at home since October to help the Catalans climb to 17th, two points clear of the drop zone.
Sevilla, fifth and level on 55 points with fourth-placed Getafe, could have moved three points ahead of the Madrid side but struggled in Catalonia.
Bernardo Espinosa headed against the bar in the first half as Girona impressed, while Sevilla failed to find their rhythm.
Eventually the deadlock was broken in the 62nd minute by Portu, who was close to signing for Sevilla in the last close season.
The Girona forward put the finishing touch to a well-worked break to ease the pressure on coach Eusebio Sacristan, ending a six-match losing streak.
"We have lost an important opportunity and there's nothing else we can do apart from think about the next game," said Sevilla coach Joaquin Caparros.
"We did not play well and must lift ourselves to think about Friday's clash."
In Valencia, Charles struck in the 93rd minute to leave the east coast side sixth.
His late strike ensured Eibar cannot be relegated this season.
The forward raced onto a loose header in the area to slot past Neto, settling a tight match.
Valencia fans whistled their team as they struggled against Eibar and in the end the Basque side merited their victory, always quick and dangerous on the counter-attack.
Even though their hopes of qualifying for the Champions League via La Liga have been dented, Valencia can still get there by triumphing in the Europa League. They visit Arsenal in their semi-final first leg on Thursday.
"We had to win to put ourselves fourth and we didn't," said Valencia coach Marcelino.
"We are sad because we had high hopes for this game [but] we need to get back up quickly because on Thursday we play again."
Getafe coach Jose Bordalas was sent off in his team's defeat at Anoeta, protesting against two penalty claims not given to his team.
Willian Jose sent Real Sociedad ahead from the penalty spot with Mikel Oyarzabal netting the second shortly after half-time.
After Hugo Duro went down in the box after being caught in the face by Willian Jose, the video assistant referee (VAR) did not oblige Getafe with a spot-kick.
Then Sociedad goalkeeper Geronimo Rulli brought down Jaime Mata in the second half and again VAR did not tell the referee to award a penalty, with Bordalas dismissed for his furious protests.
Samu Saiz pulled one back for Getafe at the death but it was not enough for the furious visitors.
Rayo Vallecano inflicted an embarrassing defeat on neighbours Real Madrid which leaves the European champions 18 points behind league leaders Barcelona, who sealed their title win on Saturday.
It was the first time the minnows had beaten Real in La Liga since 1997 and helps keep Rayo's slim hopes for survival alive.
Paco Jemez's side are 19th, six points from safety with three matches remaining.
Embarba slotted home from the penalty spot after Madrid defender Jesus Vallejo was penalised for a shirt pull.
"We couldn't do it, we're going to have to keep working and try to finish as high up the table as we can," said Vallejo.
"You have to give 100 per cent every time you play and enjoy this profession."
Earlier Villarreal drew 1-1 with Huesca, with both goals netted in spectacular fashion.
The hosts took the lead through Pablo Fornals, who scored with a rabona flick after good work from Samuel Chukwueze.
Huesca equalised through Chimy Avila, who volleyed home spectacularly in the 78th minute.
Villarreal, 14th, are five points above the relegation zone while Huesca, bottom, are seven points from safety.