The Portuguese forward and compatriot Fabio Coentrao looked to have wrapped up the points for the hosts but a late equaliser from Juan Angel Albin stunned the Bernabeu faithfulReal Madrid failed to close out the game as they stuttered to a 2-2 draw at home to Espanyol.
Los Merengues' midweek malaise looked set to continue in the capital as Sergio Garcia gave Javier Aguirre's side the lead in the 31st minute. Goals from Portuguese pair Cristiano Ronaldo and Fabio Coentrao relieved the Santiago Bernabeu faithful but a late equaliser from Juan Angel Albin ensured more points were dropped by the hosts, who had been hoping to take advantage of the fact that Liga's top two, Barcelona and Atletico Madrid, were meeting at Camp Nou later in the evening.
Ronaldo, who started the game as a striker, was finding plenty of space in the early exchanges. After firing wide in the second minute, he fed Luka Modric in space on the left but the Croatian fared no better, shanking his shot past the far post.
Los Blancos were running into a lot of congestion in the centre of the opposing half but great first touch from Modric enabled to work the space to get a shot away. His strike arrowed towards the bottom corner but despite beating Kiko Casilla it only rattled the post.
Yet the defensive complacency that had allowed Simao in earlier in the half reared its head again in the 31st minute, and this time it proved costly. Verdu slid a pass up to Garcia, who bullishy raced through a big hole left by Sergio Ramos and Pepe before adding a cool finish to silence the stadium.
Ronaldo was denied by Casilla in the 40th minute after an exquisite Ozil pass but he got the equaliser on the stroke of half-time. Sami Khedira's delivery found the 27-year-old at the back post and he beat Javi Lopez to the cross to stab the ball into the net.
Jose Mourinho clearly had strong words for his players during the break as the emerged for the second half with renewed vigour.
It took them just three minutes to go ahead as Ronaldo picked out Coentrao with a lovely reverse pass as he surged into the area. The left-back controlled the ball tightly before sweeping a low shot past Casilla.
The keeper did well not to let the game get away from his side with a trio of excellent saves, first from Alvaro Arbeloa, and then twice from Angel di Maria, the second of which was a deflected effort that was tipped onto the bar.
Casilla continued to thwart the hosts' attempts to find a third in a pulsating second half, this time keeping out Ozil with a brilliant near-post stop, after a delightful pass from Di Maria had put the German in on goal.
But Madrid were unable to hold out for the win and second-half substitute Albin was in the right place at the right time to slot home after a goalmouth scramble in the 88th minute.
Defeat means Mourinho's men will need a favour from their city rivals Ateltico, who can stop Barcelona opening a 14-point gap at the top of La Liga with a win at Camp Nou.