Real Madrid's delegate and former player Chendo (2nd L) fights with Barcelona's goalkeeper Victor Valdes (3rd L) during their Champions League semi-final first leg soccer match at Santiago Bernabeu stadium in Madrid, April 27, 2011. [Photo/Agencies]

Messi's 179th goal moved him ahead of Josep Samitier to trail only Cesar Rodriguez (235) and Laszlo Kubala (196) in goals scored for the club.

"At 23 ... That's incredible," Guardiola said.

Both coaches had stoked tensions on the eve of the match, with Guardiola launching an expletive-filled attack against Mourinho, and the ill-will spilled over into the match.

Substitute Barcelona 'keeper Jose Manuel Pinto was the first to be sent off for a red card at halftime as the two teams skirmished while leaving the field.

Pinto's sending off left Barcelona without a reserve 'keeper as the frustration of being unable to exploit 70 percent of the possession in the first 45 minutes seemed to boiled over.

Pepe was then harshly sent off after clashing with Daniel Alves as he lunged for a ball and Mourinho was sent to the stands for sarcastically clapping and showing a thumbs up to the fourth official.

"If you know football you know that's not a yellow card," said Madrid winger Cristiano Ronaldo, who was limited to testing Barcelona 'keeper Victor Valdes with a dipping shot before the half and a header over the bar after the restart. "The coach was set to make changes over the last 20 minutes."

Barcelona dominated possession as expected from the start and Madrid defended while looking for an opportunity to counterattack, which only materialized when Emmanuel Adebayor came on at the start of the second half.

The visitors patiently threaded the ball around and David Villa and Xavi Hernandez nearly put the Catalans ahead with good chances as Madrid clamped down the center with Pepe sticking to Xavi and Messi.

Tensions finally boiled over in the 40th when Madrid defender Alvaro Arbeloa was booked after a tussle with Pedro Rodriguez, while Alves was shown a yellow card for a push on Angel di Maria.

As the second-half minutes ticked down, Madrid looked set to succeed in frustrating Barca, but Pepe's expulsion complicated things.

Mourinho took a seat in the first row behind the dugout and began scribbling instructions that were passed to assistant coach Aitor Karanka as he looked to reshuffle his team in the absence of his defensive lynchpin.

But there was no stopping Messi, whose second goal was a wonderful example of his trademark darting run and finish.

Madrid stumbled against Barcelona again at the Bernabeu, where it hasn't beaten Barcleona in nearly three years- a run of four games.