 Mesut Özil opened the scoring before Alexis Sánchez scored two goals in eight minutes.Substitute Andy Carroll headed home to give the hosts hope but it was determined for three points to go Arsenal's favour as Alex Oxlade-Chamberlain struck a 25-yard strike before Sánchez completed his hat trick, sprinting through the West Ham defence and chipping in.Three days later was the Gunners' final Champions League group match against Basel in Switzerland.