Madrid spent the majority of the game in charge and took the lead early on through Mesut Ozil, only to go into the break behind after Barca strikes from David Villa and Lionel Messi.
A rare goal from Xabi Alonso brought them back on level terms, and the Whites created plenty of chances from which they could have taken a lead to Catalonia on Wednesday for the second leg.
But Barcelona, without several key players through injury, held on and will fancy their chances to best their fierce rivals in the traditional league champions vs cup winners tie for the very first time in five attempts.
The home side, appearing more determined to get the better of their rivals every time they meet, sprinted out of the blocks in this first leg and would have taken the lead on nine minutes but for a superb save from Victor Valdes to deny Karim Benzema from Cristiano Ronaldo’s pinpoint cross.
Valdes could only delay the inevitable by four minutes, however, with Benzema this time playing provider to tee up Ozil to give Madrid a deserved lead.
Jose Mourinho’s men remained in control for the majority of the first half, and despite Sami Khedira picking up the only booking of the opening 45 for persistent fouling, the Whites had further efforts on goal through Ronaldo and Benzema, while Sergio Ramos also came close from a set piece.
But then Messi, uncharacteristically quiet in the opening half hour, then played a diagonal pass to Villa on the left corner of the penalty area in the 36th minute from which the striker unleashed a wonderful curler into the top corner beyond a helpless Iker Castillas for 1-1.
Benzema almost restored his team’s lead minutes from half-time but for a superb interception from makeshift centre-back Javier Macherano, and then at the opposite end the game soon turned on Real.
Messi, sparked into life by his assist, got himself a piece of the action taking on several white shirts and a fortunate deflection left him clean through in the box, from which the Argentine made no mistake seconds into time added on at the end of the first period.
Far from deterred by the shift in momentum, the home side came out for the second 45 just as they had at the game’s beginning, and were soon rewarded.
In the 54 minute, one of many Madrid corners fell at the feet of an advanced Pepe, and with his back to goal the defender teed up Alonso for a well-placed shot to beat an outstretched Valdes and draw his side back to level terms.
It was almost another quickfire turnaround minutes later when Valdes foolishly rushed out for a cross, only for Benzema’s header to flash across goal with the far post area screaming out for a finish.
Benzema again used his head on 67 minutes, forcing a catch from Barcelona keeper from an exquisite Ozil centre, but the new, fitter and hard-working French forward was soon replaced by Gonzalo Higuain for the home stretch.
And inside the final ten minutes, both sides appeared to have clear-cut penalty shouts turned down: first, Valdes appeared to reach at Ronaldo’s legs as the Portuguese talisman collected a poor parry by the stopper.
Then, within four minutes of the first controversial incident, substitute Pedro was quite clearly taken out by Marcelo inside the box as he prepared to shoot at goal, once again to no whistle from the official.
At the very least, the missed fouls were fairly balanced. Unlike the game as a whole, which Real controlled for large portions only to find themselves heading to Camp Nou during the week with no advantage as both sides seek their first silverware of 2011/12.