We went down 3-0 via Gilberto's two penalties - both decisions questionable - and Emmanuel Adebayour's opener, a marginal offside decision that went the Gunners' way.
However, as skipper Ledley and boss Martin Jol later conceded, those goals couldn't cloud the fact that we just didn't get started in the game.
"We're all disappointed, especially for the fans," said Ledley. "We know this is the big game for them.
"We were all up for it before the game but we didn't put in the performance we wanted to, simple as that.
"To lose the first goal as we did after 20 minutes put us on the back foot and it became a difficult game for us from that point.
"Everyone is gutted and we just weren't good enough on the day. You get caught up in the game and the emotions of the game and don't always do the right things. We didn't do the things we were supposed to do and we got punished."
Ledley King's first thoughts were with our fans after the derby defeat at the Emirates Stadium.