Mikel Arteta lauded the maturity of his "fantastic" Arsenal side after they sent a message with a first Premier League win over Manchester City since 2015.Gabriel Martinelli’s deflected effort in the 86th minute ended the Gunners’ run of 12 consecutive top-flight defeats to Pep Guardiola’s side.It helped Arsenal leapfrog City in the table to finish the weekend as joint leaders and while Guardiola insisted his champions are happy to chase again as they did successfully last season, it felt like a potentially decisive early blow had been landed between two title rivals.