This was Arsenal's first major test against rivals who had also won their opening two matches, and they passed it after exposing Chelsea's defensive vulnerabilities. Along with Manchester City, the Gunners are one of only two teams to have a 100% winning record after three games - but their latest success came after an unexpected setback. Arsenal's first league title for 22 years was built on their stubborn defence and there will be questions about how they conceded so early against their London rivals.