Sanchez double helps keep Arsenal's hopes alive

By Mike Collett LONDON (Reuters) - Alexis Sanchez scored twice and Mesut Ozil headed the other goal as never-say-die Arsenal beat Dinamo Zagreb 3-0 on Tuesday and kept alive their hopes of reaching the Champions League last 16 for a 16th straight season. The Gunners, whose chances of advancing looked remote after defeats by Dinamo, Olympiakos Piraeus and Bayern Munich in their opening four matches, were given a huge helping hand by Bayern Munich who thrashed the Greeks 4-0 in the other Group F m