Cliftonville boss Jim Magilton said his side's display in their 2-1 loss against Glenavon was "unacceptable".
Ryan Curran fired the Reds in front at Mourneview, but their lead lasted just six minutes as Paul McGovern levelled for the Lurgan Blues.
Lewis Ridd saved Nathaniel Ferris' penalty before Harry Murphy scored what proved to be the winner as the Reds fell to a second successive league defeat.
"Unacceptable. Substandard. Awful from start to finish, even though we gave ourselves a head start. I thought we were really poor man for man. The opposition deserved to win," he told BBC Sport NI.
"They showed more appetite in the game. Albeit we created some really good opportunities, I still thought we were awful."
Cliftonville are without a league win since 13 December and Magilton was critical of his side's inability to fight back in the second half after going behind.
"Showing appetite and desire is non-negotiable. Glenavon are fighting for their lives. Some of those lads are fighting for their very legs at their football club. I'm not going to accept that. Not from us," he added.
"We didn't play well at all. In fact, we were awful, and that encourages the opposition. They stay in the game."
"We talk about attitude and character. That was nowhere near the levels. Nowhere near."
Magilton has called on the Reds to respond in the Irish Cup sixth round next week when they face Glenavon again, this time at Solitude.
"What we produced today was pitiful. Next week, we have to show what that shirt means. It's as simple as that.
"Glenavon will come here ready to stand up and be counted. It's a big game for them, and it's a massive game for us too. We'll see how we go."
