Barcelona talisman Lionel Messi scored two late goals to put his side in control of their bad-tempered Champions League semi-final against Real Madrid.
The goals came after Real's Pepe was dismissed in the 61st minute and boss Jose Mourinho was sent to the stands soon after for his protestations.
That seemed to turn the tide in Barca's favour and they went ahead when Messi turned in Ibrahim Afellay's cross.
Messi then added a fabulous second when he ran 30 yards before slotting in.
It was a glorious way to score his 11th goal in 11 Champions League games and by doing so made his side firm favourites to go through from the second leg at Barcelona's Nou Camp on 3 May.
The final against either Manchester United or Schalke 04 will be played at Wembley on 28 May.
Up until he scored his first goal in the 76th minute, Messi was operating around the fringes of Real's final third, which was difficult to breach for much of the match.
The visitors only managed to break clear of the snapping Real defence on a couple of occasions during the first half.
Xavi's firm but telegraphed shot was well held by Iker Casillas, who was left floundering when David Villa's low, whipped shot from 20 yards beat him but also the right-hand post.
The Spain keeper then came to the home side's rescue when he dived low to block a Villa shot after Messi had played a threaded reverse ball to the striker.
Real were content to sit back and frustrate their visitors, much to the annoyance of their own lone forward Cristiano Ronaldo.
His supply line was virtually non-existent as Mesut Ozil, Xabi Alonso and Angel di Maria were occupied with defensive duties.
So when Real did finally test Victor Valdes, it needed Ronaldo to drop deep, pick up the ball and then venture forward before launching a trademark long-range drive that the Barca keeper did well to parry away.
Goalmouth action was scarce in the opening half but on-the-ball and off-the-ball incidents were not, as many had predicted.
Referee Wolfgang Stark kept a cool head while the melodramatics unfolded around him, but his resolve was finally broken when, after the half-time whistle, there was a fracas on the touchline as the players were leaving the field, which resulted in Barcelona substitute keeper Jose Pinto being shown a red card.
It was still 11 v 11 on the pitch after the interval, but Real were soon reduced to 10 when the influential Pepe was sent off for a high tackle on Dani Alves.
Real coach Mourinho, who was seen to mouth sarcastically "well done" to the fourth official and was subsequently dismissed himself, now faced a defensive problem.
Before he had time to put a new structure in place, Villa was in again to test Casillas with an angled shot that was brilliantly palmed away.
The 10 men of Real appeared to be holding out, if not entirely comfortably, until the magnificent Messi made his move.
The pacy Afellay, who came on for the injured Pedro, sped down the right and played an inviting square ball into the area which Messi reached ahead of Sergio Ramos and tapped in at the near post.
Despite conceding an away goal, Real would have considered themselves to be still in the tie. But then Messi struck again with pure brilliance.
The Argentine forward picked up the ball midway inside the Real half, skipped past Lassana Diarra, Raul Albiol and Marcelo before slotting in his 52nd of the season and what could prove to be the decisive goal of the tie.