had a provocation to respond to. In boxing they used to say it was a bad idea to hit the young Mike Tyson early in a fight because it just made him angry and hastened the moment of doom. Andrey Arshavin's winning goal in north London three weeks ago had a similarly counter-productive feel. What if it brought Guardiola's Bara past the tiny Camp Nou chapel and on to the pitch like Catalan dragons, looking for a Premier League side to burn? While Mascherano provided defensive security in front of a back four missing Carles Puyol and Gerard Piqu, the light fell on Messi to show that no team can cope with him when the mood grips him. His unplayability is what sets him apart. In his best form, a chasm opens between the game he is playing and the sport those around him are endeavouring to master. This was the call to him, on a night of artistic friction. The mission was to blind Arsenal with skill, movement, finesse, audacity. In Theo Walcott's absence Arsenal lacked the spearing penetration of the first leg, when they twice broke free to overturn Barcelona's lead. Van Persie played like an old-school No9 but a revamped home defence seldom back?pedalled. Instead their midfielders tried to thread passes beyond the oncoming Arsenal throng. Crosses were over-hit, dribbles carried on too long and shots mis-hit until Messi's feet regained their softness, their dexterity, and Barcelona headed for their dressing room in the ascendancy. The props