Manuel Pellegrini harangued Swedish referee Jonas Eriksson as he came off the field, the Manchester City manager furious that Barcelona had been awarded a penalty for a foul by Martin Demichelis on Lionel Messi that was outside the area.
ellegrini should also have been livid with himself for starting Demichelis.
The decision to field the sluggish Demichelis against Messi backfired. Demichelis was rightly dismissed. Messi converted the penalty, and City's 10 men fought hard but eventually succumbed to another goal from Dani Alves.
According to one leading referee last night, Eriksson's decision was correct as momentum counts but the final score told of City's tough task in the Camp Nou second leg when Pellegrini's tactics will be tested even further.
For 54 minutes, Pellegrini's tactics had worked. City had defended well, intelligently, judging their interceptions shrewdly but the flaw was always there, as City fans had pointed out before kick-off. Demichelis lacks the pace to deal with the world's leading strikers.
City fans and onlookers like Gary Lineker felt it was an accident waiting to happen; he did superbly at one point in the first half, ushering Alexis Sanchez away from goal but he represented City's Achilles heel and was sadly involved in the defining moment of the first leg.
When Andres Iniesta played that wonderful pass through, Messi had watched the positioning of City's defenders. Messi made his move, running on to Iniesta's pass, getting ahead of Demichelis, who brought him down. The offence began outside of City's area but Messi's momentum took him into the box and down.
The Swedish referee, Jonas Eriksson, had no hesitation, pointing to the spot, assisted by two other officials checking on incidents in the box. Demichelis hardly waited for Eriksson's red card, turning and walking to the tunnel. Messi, meanwhile, calmly stroked the penalty past Joe Hart.
Whatever City's legitimate grievances about the location of the offence, the fact remained Pellegrini had gambled by starting Demichelis ahead of Joleon Lescott. Joleon Lescott might have had the pace to stick with Messi.
City fans had been waiting for this moment. They even applauded Messi after a dazzling passing session with Dani Alves during the warm-up. Within two minutes, the pair combined again, Messi releasing Alves into the area but Gael Clichy cleared up. It seemed to set the tone for the first half, largely of Barcelona possession and expert City defending but the hosts also broke out, threatening through Alvaro Negredo.
Demichelis apart, Pellegrini's changes had made sense. He tweaked his usual 4-4-2 system, flooding midfield and inserting Aleksandar Kolarov in front of Clichy to guard against Alves' runs.
David Silva was dropping off the lone striker Negredo, darting back to help his midfield, making sure they were never outnumbered when Xavi started building. City players were ready, refusing to be overawed by the visit of the four-time champions of Europe. At the back, as Barcelona flowed time and again towards Hart's area in the first half.
City were under huge pressure early on as Barcelona dominated possession, the ball speeding between Messi, Xavi, Iniesta, Cesc Fabregas and Alexis Sanchez.
After 15 minutes, City began to believe more. Yaya Toure went on a storming run. Silva then released Negredo, who chipped the ball across but City were without the injured Sergio Aguero. He would have been there, feeding on such moves. City need Aguero back for the trip to Catalonia, even more with Barcelona having that away goal.
City were working so hard, Jesus Navas earning cheers for closing down Jordi Alba, who hurried his clearance. City's quick movement on the occasions they acquired the ball brought some hope. Clichy went flying forward and was tripped by Alves. Silva lifted the free-kick in, Valdes eventually clutched the ball under pressure from Toure.
Negredo tested Valdes with a snap-shot. City were pressing higher, faster, but Barcelona were mocking Mourinho's disparaging verdict of them.
Fernandinho was very fortunate to escape a booking for a clear foul on Fabregas, which would have ruled him out of the second leg. City kept hounding Barcelona. Toure closed down Iniesta as he dribbled across the box. City were defending impressively, restricting Barcelona to onlyone real chance before the interval. Xavi let fly from 25 yards, almost catching Hart out. The England keeper pushed the ball up and then grabbed it before it fell out for a corner.
Kompany then fouled Messi, whose ensuing free-kick thudded into the wall. City weathered these storms and hit back. Negredo headed wide from a Clichy cross. Javier Mascherano then wrapped an arm around Negredo, sending him over but Eriksson deemed it accidental. Kolarov went in two-footed on Busquets, receiving only a yellow.
Then there was that great, and deceptive piece of defending from Demichelis, who hustled Alexis Sanchez wide and then slid in, forcing the ball to safety. Demichelis even sold Messi a dummy.
But nine minutes into the second period, Messi was running past Demichelis as if he were a tailor's dummy. Trailing by a goal, and down to 10 men, Pellegrini sent on Lescott for Kolarov and Samir Nasri for Navas.
The home fans chanted "we're Manchester City, we'll fight 'til the end" and they went close to an equaliser. Silva was marvelous in the attempted fight-back, testing Valdes.
With 12 minutes left, Barcelona had good reason to feel shortchanged by the officials when Fabregas was flagged offside when setting up a goal for Gerard Pique. Fabregas was played on by Clichy. They collected their second goal in the last minute, surely settling the tie.
Neymar, who had replaced Alexis Sanchez, passed to Alves, who ran into the box and rolled through Hart's legs and in. City need Aguero – and a miracle. (© Daily Telegraph, London)