Piotr Trochowski lashed home after 69 seconds to secure a 1-0 victory for the hosts and condemn Real to their second successive defeat.
Mourinho now faces the task of picking his players up for the visit of Premier League title-holders Manchester City in the Champions League tomorrow night.
“From the first to the last minute we were poor,” the Portuguese coach said.
“We were bad in the first half and we were bad in the second half too. They really deserved the win and we deserved the loss more.
“Congratulations to them — we got what we deserved for how badly we played. At this moment I have no team.”
Mourinho came out in defence of Cristiano Ronaldo, however, saying he cannot be blamed entirely for Real’s poor form and suggesting other individuals are also lacking commitment at present.
The Portuguese forward has been at the centre of speculation about his future after revealing earlier this month he did not celebrate his two goals against Granada because he was “sad” for professional reasons, but without elaborating.
“I don’t think that the rumours of the last couple of weeks have anything to do with it,” Mourinho said.
“It is about a state of mind and of two or three who aren’t thinking like the rest.
“They are the minds of players which are not committed and for whom football is not a priority in their lives.
“There aren’t many involved and it’s complicated, but I’m coach and if there are those less committed then it is my fault.”
Barcelona defender Gerard Pique, meanwhile, has tried to put his side’s stunning start to the season in perspective, although he is keen to see the Catalan side keep their winning run going.
Tito Vilanova’s men made it four wins from four with a 4-1 thrashing of Getafe on Saturday night.
Lionel Messi scored twice off the bench for Barca while David Villa and Adriano were also on target in a one-sided display, although Pique was quick to remind his team-mates the season has only just got off the ground.
“We’ve only played four games, this [the gap over Real] isn’t that important.
“We’re feeling good, though. We’ve won four out of four games. We have to continue like this.”
In Italy, Juventus came from behind yesterday to extend their perfect start to the season with a comfortable 3-1 win at Genoa — but Napoli, Lazio and Sampdoria remain on the pace with the champions after victories.
Juventus had to come from behind to defend their lead in the Serie A standings after Ciro Immobile put Genoa in front in the 18th minute.
Emanuele Giaccherini brought the Bianconeri level after an hour, while Mirko Vucinic and Kwadwo Asamoah added a second and a third to make it three wins out of three for Juve.
Napoli also claimed a 3-1 win to maintain their 100% start against Parma.
Walter Mazzarri’s men were in control from the moment Edison Cavani netted a third-minute penalty and, with Goran Pandev and Lorenzo Insigne also on target, Marco Parolo’s strike was rendered worthless.
Lazio are third after a 3-1 win over Chievo at the Stadio Marcantonio Bentegodi.
Hernanes was the star of the show, scoring twice in either half, while he also set up Miroslav Klose for his strike for Vladimir Petkovic’s side.
Sergio Pellissier netted a late penalty for the hosts.
Sampdoria also boast three wins from three after a 3-2 triumph at Pescara.
In yesterday’s late kick-off, Inter Milan picked up their second away win of the season thanks to a 2-0 victory at Torino.
Diego Milito put the Nerazzurri ahead in the 14th minute and they resisted a spell of pressure from the home side before Antonio Cassano added the second seven minutes from full-time.