Mikel Arteta hailed Arsenal’s first half of the Premier League season as “extraordinary” following their last-gasp victory over Manchester United which kept them five points clear at the summit.The Gunners ran out 3-2 winners following Eddie Nketiah’s late effort, meaning they have now amassed 50 points at the halfway point of this domestic campaign. But despite their lead at the top of the table, and impressive season so far, Arteta insists closest challengers Manchester City remain the standard bearers.