Barcelona took control of their Champions League last 16 tie against 10-man Manchester City on Tuesday when they won 2-0 at the Etihad Stadium thanks to a Lionel Messi penalty and a late strike from Dani Alves.
Messi, tripped running into the box by Martin Demichelis, which earned the defender a red card, scored after 54 minutes to give the four-time European champions the lead over City, who were playing in the knockout rounds for the first time.
Alves scored in stoppage time when he shot through the legs of City goalkeeper Joe Hart after a marauding run down the right.
The visitors dominated the opening 20 minutes and finished far stronger against City, who seemed overawed by the occasion.
The two sides, who had scored 228 goals between them this season heading into the game, failed to produce the goalfest that many expected.
The two away goals Barcelona did score, however, have given them a huge advantage going into the second leg on March 12.
"People have been saying this is not the same Barcelona of previous years but we've got a great a result tonight and we've proved a point to some people," Barcelona midfielder Cesc Fabregas said.
"We are not there yet, though. They are a good team and we still have to work hard to get through."
The visitors quickly silenced the home fans, who created a superb atmosphere before kick off, by totally dominating possession in the opening 20 minutes when City hardly saw the ball and barely ventured into Barca's half.
Barca played their typical quick-passing game and although they never allowed City to break out of defence, they also never created a serious goal attempt of their own as the hosts stayed organised and were well-marshalled at the back by Vincent Kompany.
City finally escaped their shackles midway through the opening half when David Silva found Alvaro Negredo with a fine angled pass, but the Spaniard's dangerous-looking cross failed to find a target.
From then on City gained in confidence and put Barcelona goalkeeper Victor Valdes under pressure when he flapped at a high ball.
Yet City's only real chance came in the 27th minute when Negredo turned and shot straight at Valdes from the edge of the penalty area.
Barca's best chance before the break fell to Andres Iniesta, who forced a save from City keeper Hart from 20 metres out.
The balance tipped Barca's way with Demichelis's 53rd-minute dismissal, which will keep him out of the second leg at the Nou Camp.
The defender appeared to have fouled Messi outside the area, but referee Jonas Eriksson pointed to the spot and showed Demichelis a red card, allowing Messi to stroke the ball past Hart to put the visitors ahead.
Barca largely regained control of the match after the goal with City's best chance of an equaliser coming when David Silva chested down and volleyed straight at Valdes in the 77th minute.
"Two-nil is very tough on us. When it was 11 versus 11 we were in the game but with a man less and with their individual quality which is so high it was very hard," Manchester City captain Kompany said.
"If they play as they can in the second leg it will be very hard but we still have a chance."