The home side’s response to Chelsea’s early goal was to play breathless attacking football We’re back, baby. So, so back. Well, OK, not exactly back. But back down the time tunnel, for a while at least, as on a powder blue afternoon at the Emirates Stadium, Arsenal and Chelsea produced an opening half-hour that felt like a throwback to prime Barclays of the early 2000s. In that period this really did feel like a twist on a classic: spells of midfield murder-ball, stretched and flustered full‑ba…