Arsenal have extended their winless streak to seven for the first time since 1992 after losing to Eintracht Frankfurt in the Europa League on Thursday.
The Gunners lead at half-time thanks to Pierre-Emerick Aubamayang, but were a completely different side after the break.
Eintracht Frankfurt capitalised through Daichi Kamada, who scored a quick-fire to stun the hosts and claim 2-1 victory.
Speaking after the game, Emery was disappointing his side allowed Frankfurt to takeover the match.
He told BT Sport: "Tonight wasn't our moment but we won a lot of matches to be top of the group. Our aim is to win away to Standard Liege to finish as first.
"We want to do that to build our confidence and connect with the supporters. We need to win and we lost a very good opportunity. We didn't do enough to win this match.
"We lost our control of the game for 15 minutes of the second half, and they scored two goals. Then we had injuries, and Mustafi going off meant I wasn't able to make changes. We were better in the first half but in those 15, 20 minutes we lost control."
