The prolific hitman hammered home an exquisite volley five minutes after replacing Thierry Henry as Real were left to rue several squandered chances that allowed Barca to open up a two-point lead at the top of La Liga.
Sergio BusquetsÃ¢â‚¬â„¢ second yellow card saw the Catalan club reduced to ten men just after the hour mark following his foolish decision to handle the ball, but Real were unable to make the man-advantage pay and their frustrations boiled over as Lassana Diarra received his marching orders at the death.
Lionel Messi Ã¢â‚¬â€œ who had recovered from a thigh injury Ã¢â‚¬â€œ and Cristiano Ronaldo started the game but the first half proved a largely disappointing affair.
Real created the better chances and should have been in front on 20 minutes after Kaka fed Ronaldo the ball inside the 18-yard box.
The Portuguese superstarÃ¢â‚¬â„¢s low effort required a fantastic save by Victor Valdes with his trailing leg to deny him a perfect return following a lengthy and frustrating injury lay-off.
Barca lacked an attacking spearhead throughout the half with the ageing Henry, who regularly drifted into the left channel, unable to attack the ball on the occasions it was played across goal.
The game was proving a fairly scrappy affair considering the amount, and value, of talent on display, but Real were able to carve out another opportunity short of the half-hour mark.
Another move involving Ronaldo and Kaka saw the Brazilian find his fellow countryman Marcelo inside the 18-yard box, but a poor touch allowed Carlos Puyol time to dive across and get a block in just as the winger pulled the trigger.
A feature of BarcaÃ¢â‚¬â„¢s play in the first half was to search out Henry on the left flank and it almost came to fruition when the former Arsenal legend chipped in a cross that had Iker Casillas scrambling to tip the ball over the bar.
Despite BarcaÃ¢â‚¬â„¢s domination of possession and flashes of brilliance from Messi, Real had proved the most dangerous side as the half came to a close.
Messi began the second half in similar fashion to the first by cleverly turning Diarra before being cynically pulled back by the former Portsmouth man Ã¢â‚¬â€œ an infringement that earned him his first yellow card.
Six minutes after the restart, Guardiola sent on Ibrahimovic to the raucous applause of the 98,000 home crowd and his presence provided an immediate lift for the team as Barca forced a corner.
However, Real were able to clear their lines and break on the home side through Gonzalo HiguainÃ¢â‚¬â„¢s surge forward.
The in-form Argentine raced towards goal before playing a one-two with Ronaldo and fainting past Eric Abidal to shoot at goal, but was thwarted by another last-ditch block by the inspired Puyol.
Three minutes later, Ibrahimovic was to mark his first Ã¢â‚¬ËœEl ClasicoÃ¢â‚¬â„¢ appearance in spectacular style.
Dani Alves had time and space to search out the elegant striker as he emerged unmarked at the far post to emphatically thump a volley on his weaker left side into the net and past a stranded Casillas from six yards.
The Camp Nou erupted but their jubilation was to be hampered following Busquets moment of madness that saw him take an early bath on 63 minutes.
The sending-off instantly stretched the game as Real began to take the game to Barca.
Marcelo found space on the left and delivered a cross for Ronaldo to rise high and head at goal, but the current World Player of the Year failed to keep his header down and it sailed over the bar.
It was to be his last involvement in the game as his lack of match fitness became apparent and he was replaced by Karim Benzema on 66 minutes.
Moments later, Messi miraculously turned away from the attention of three Real players before jinking past Pepe who then bundled him to the ground.
Xavi curled the subsequent free-kick into the far post and onto the head of Gerald Pique, but the former Manchester Untied defender could only direct his free-header tamely wide of the post.
Barca had another chance to double their lead on 76 minutes. A period of patient one-touch football resulted in Abidal latching onto XaviÃ¢â‚¬â„¢s through pass before driving the ball across the face of the goal and only just wide of CasillasÃ¢â‚¬â„¢ left-hand post.
Real were able to muster one final chance with ten minutes left on the clock.
Xabi AlonsoÃ¢â‚¬â„¢s corner-kick found its way through the melee to Benzema but the French international blazed over the bar from close-range under close attention from Pique.
As the game drew to a close Real president Florentino Perez was seen in the stands looking to the sky in despair and his anguish was almost compounded in the final minute after Dani Alves threaded a pass across goal into the path of Messi.
The effervescent forward struck the ball first time but was denied a goal to cap a sublime display brilliantly by the out-stretched boot of Casillas.
A period of keep-ball by Barcelona towards the corner flag saw frustration get the better of Diarra and he chopped down Xavi to bring a thoroughly entertaining half to a close with his second yellow card of the evening.
Barcelona: Valdes, Dani Alves, Puyol, Pique, Abidal, Busquets, Xavi, Keita (Toure, 66), Iniesta, Henry (Ibrahimovic, 51), Messi
Real Madrid: Casillas, Sergio Ramos, Pepe, Albiol, Arbeloa (Raul, 74), Lass, Alonso, Ronaldo (Benzema, 66), Kaka, Marcelo, Higuain
Man of the Match: Zlatan Ibrahimovic Ã¢â‚¬â€œ Exquisite match-winning goal to condemn his sideÃ¢â‚¬â„¢s arch-rivals to defeat and open up a two-point lead at the La Liga summit.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news