Arsenal boss Mikel Arteta says defeat at Fulham was a "sad day".
The Cottagers won 2-1 as Raul Jimenez and Bobby Cordova-Reid struck after Bukayo Saka had given Arsenal the lead.
Arteta said, "Really tough day. A sad day. Three days ago [2-0 defeat by West Ham] we played a game we lost that we completely meant to win it, today was our worst game of the season. The pace, the purpose we have in attack, defensively we were second best, we could not dominate and had issues because of that.
"We didn't do enough with that [possession] - not enough purpose speed or threat. We were sloppy with the ball. It wasn't good enough. We didn't deserve to win. When you have opportunities to go top of league on 31 December and now end up with really bad feeling that is football. The lines are really thin.
"If we play like we played in the other 19 games we will be up there [in the league at the end of the season]. If we play like today we will be nowhere near. Today was a really difficult day to swallow."
