When looking back at the moments which led to the modern rivalry between Manchester City and Arsenal, you have to cite September 12, 2009.
That was the day Emmanuel Adebayor sprinted the length of the pitch to celebrate in front of Arsenal's fans, who responded by throwing whatever missiles they could find in the Etihad away end.
I cautioned Adebayor for inciting that small riot, of course, but it is amusing to think that infamous celebration might never have happened were it not for what I decided to do seconds earlier.
Shaun Wright-Phillips had been fouled by Gael Clichy over on the right wing. My assistant had flagged for the foul but I signalled for the advantage to be played.
Wright-Phillips got up off the ground, crossed the ball, and Adebayor headed it beyond Manuel Almunia before all hell broke loose.
Emmanuel Adebayor sprinted the length of the pitch to celebrate his goal against Arsenal
The striker had been cautioned by Mark Clattenburg for inciting anger in the away end
Anthony Taylor should be prepared for a fiery encounter and to be blamed by the managers
All three of the Premier League games I refereed involving these teams were full of fireworks - none more so than that 4-2 victory for City - and Anthony Taylor should expect a fiery encounter given what is at stake.
Taylor should also be ready to be blamed by Pep Guardiola or Mikel Arteta if anything controversial occurs.
Like in October 2010, when I showed City's Dedryck Boyata a red card for fouling Marouane Chamakh after five minutes as Arsenal went on to win 3-0. Roberto Mancini told me I was wrong, Arsene Wenger told me I was right, but this was back when last-man fouls resulted in reds, so I know it was the correct call.
Or in September 2014, when Manuel Pellegrini told me both of Arsenal's goals should have been disallowed for soft fouls in a 2-2 draw with City.
This is a rivalry that has developed over time, and looking back at that Adebayor incident now, I can say I played a significant part in its development via some good refereeing 15 years ago!