Oliver Glasner said Crystal Palace paid the price for too many technical mistakes after the Eagles fell to a 2-1 home defeat to Brentford.
Palace created some good chances at 0-0, but the game turned on the decision to award Brentford a penalty just after the hour mark. Bryan Mbeumo's first effort came back off the post, only for VAR to order a re-take for encroachment, which he scored.
The Eagles were then left chasing the game after Kevin Schade found space to head in a cross from Mikkel Damsgaard.
"I think the performance was ok, but ok isn't good enough," reflected Glasner. "Especially two minutes before the penalty, we made too many mistakes in our own box. We couldn't clear the ball and then we cause a penalty.
"Everything went wrong with this situation [for the penalty], but the first three or four mistakes were our mistakes. No-one is to blame for it.
"Then when you are 1-0 down against Brentford it is difficult, we didn't create many chances today.
"The reaction after their second goal was great. We got a goal from Romain then we tried everything, but we were not quite accurate enough.
"We had some set-plays, but we were not good enough in these situations to score the equaliser - and that's why we lost the game."
One bright spark for the Palace came in the form of Romain Esse's debut goal, the young winger bringing his side back into the game only a few minutes after coming on.
Glasner revealed after the game, that he had always planned to give his new signing some time on the pitch.
"Of course we had in our minds that he would get some minutes," added Glasner. "We thought we need some attacking input with Daichi [Kamada] and him, so we also changed the shape to a 4-4-2, with Eddie [Nketiah] as a second striker.
"We knew [with the goal] we could have an overload on the far post in this situation and we managed to find Daniel Muñoz. Romain had a great run, and then a nice finish, so it's good for him, giving him confidence, and it helps us for the next weeks."
Glasner was also full of praise for the home fans who stuck with the team despite a difficult second-half in atrocious weather conditions.
"Especially at the end," he added. "They pushed us forward to try and get the equaliser. So thanks for supporting us again, in not the nicest conditions.
"They stayed and believed in us. Today we couldn't give them something back, but we will do our best to get the win at Old Trafford [next week against Manchester United].
