Alexis Sanchez made the most of howlers from Wes Brown and Vito Mannone as Arsenal claimed a 2-0 victory at Sunderland. Press Association The Chile international needed no second invitation after Brown scuffed an attempted back-pass straight into his path and looked on in horror as he raced almost half the length of the pitch before beating goalkeeper Mannone with ease. And there was worse to come for the Italian, who handed Sanchez a second in injury-time as he made a mess of a back-pass. Brown looked to have the ball under control just inside his own half and turned neatly away from Sanchez in order to play it back to Mannone. However, his disastrous miskick allowed the Chilean to run through on goal and delicately chip the advancing keeper. Cazorla and Arteta both went close as the Gunners looked to kill the game off before half-time, although the home side managed to escape further damage. Whatever Poyet said during the break appeared to have an effect as his players returned in far more determined mood and set up camp much higher up the pitch. He was forced into a 50th-minute reshuffle when lone striker Steven Fletcher limped off to be replaced by Connor Wickham, and the newcomer arrived with his team enjoying their most productive period of the game to that point with midfielder Jack Rodwell forcing a save from Wojciech Szczesny with a firm header two minutes later. For the first time in the game, the Arsenal rearguard found itself under concerted pressure, although the home side’s frailty at the back invited further pressure with Brown almost serving possession up to Chambers before Van Aanholt’s aimless clearance allowed Sanchez to test Mannone from distance. Larsson warmed Szczesny’s hands with a 65th-minute drive from 25 yards and substitute Jozy Altidore looped a header towards goal from Van Aanholt’s inviting cross with 14 minutes remaining. However, the United States international fluffed his lines two minutes later when, having been picked out with a raking long pass by fellow substitute Jordi Gomez, he scuffed a volley harmlessly across the penalty area. Szczesny very nearly handed Van Aanholt on 81st-minute opportunity to level when, fearing he was about to step outside his area, he headed the ball straight to the full-back wide on the left, although the Dutchman’s long-range effort sailed wide of the far post with Mertesacker racing back to cover for his keeper. But disaster struck at the death when Mannone failed to control Buckley’s back-pass and Sanchez added a second from close range. Once again, the Black Cats, who scored three own goals in last Saturday’s 8-0 horror show at Southampton, were made to pay for self-inflicted wounds despite launching a second-half fightback in front of a crowd of 44,449 at the Stadium of Light. The home side’s humiliation on the south cost had cast long shadows and head coach Gus Poyet sent his team out demanding a reaction, although that was always going to be easier said than done against an Arsenal team packed with talent, although depleted by injury and suspension. However, the Uruguayan could only look on helplessly as his players initially struggled to shake off the trauma of their Southampton nightmare. The Gunners, predictably, retained possession with ease as Mikel Arteta and Mathieu Flamini supplied the excellent Sanchez, Santi Cazorla and Alex Oxlade-Chamberlain ahead of them to repeatedly stretch the home defence. By contrast, the Black Cats at times treated the ball as if it were a live hand-grenade as they retreated ever deeper towards Mannone. However, for all their early dominance, the visitors struggled to create clear openings with former Sunderland loanee Danny Welbeck sending a swerving, dipping 15th-minute effort on to the roof of the net after Sanchez had fired wide from distance. Poyet’s men only rarely managed to venture into enemy territory with the left flank their only real outlet, and while winger Will Buckley tested defender Calum Chambers on several occasions, it was full-back Patrick van Aanholt who forced an important 25th-minute block from Per Mertesacker after running on to Sebastian Larsson’s pass. But it was Mertesacker’s clearance which indirectly led to the opening goal.