Robin van Persie missed a penalty and Marouane Fellaini was sent off as Manchester United failed to claim an deserved win and reinforce their position at the top of group A in the Champions League.
Ryan Giggs made his 950th appearance for the Red Devils but, for all their experience and the better chances, the Premier League champions were unable to leave Spain with all three points.
Manchester United were unable to muster a clear opportunity in the first period, but vastly improved in the second and could have won the encounter by a sizeable margin.
Javier Hernandez was guilty of an awful miss with the goal at his mercy, while Van Persie later hit the outside of the right post shortly after coming on as a replacement for Wayne Rooney.
The same upright denied Van Persie soon later when his spot-kick cannoned back off the frame after Manchester United had been awarded a somewhat dubious penalty.
It was perhaps justice done for the hosts, after Ashley Young - so often derided for his theatrics - went over far too easily in the box to earn Van Persie's opportunity from 12 yards.
Fellaini saw red in the final minute after receiving second yellow card, having been involved in a number of scuffles throughout the encounter.
This was a chance for Manchester United to take a significant step towards qualification for the competition's knockout phases and, although they remain a point clear at the top, may be left to rue their inability to convert on the night.