Rangers manager Graeme Murty has claimed that his side failed to do the basics right in Sunday's 3-2 defeat by Celtic at Ibrox.
The hosts were twice ahead in the Old Firm derby via Josh Windass and Daniel Candeias, while the Hoops played more than half an hour with 10 men after Jozo Simunovic was sent off.
Moussa Dembele's effort just before half time saw the two teams head into the dressing rooms all square at 2-2 before Odsonne Edouard scored the winner for the visitors on 69 minutes.
"The people on the pitch had more than enough experience and opportunity to go and win that and we've managed to throw it away," Murty told Rangers TV after the game.
"I'm immensely frustrated for the fans and the players... I don't think we'll ever give ourselves a better opportunity to go and win the game.
"We started brilliantly and then lacked composure, got carried away with the atmosphere. They got back into it with a good hit from them but a poor goal from us. It then took 15-20 minutes for us to re-establish our composure.
"We go ahead again and then we concede an awful goal a minute before half-time. That's a fundamental flaw, an error that shouldn't happen at this level.
"The sending-off is obviously a pivotal moment and after that we lost composure in possession. We started lumping crosses in from deep rather than playing through - and once again, we give away a really, really poor goal. Basics cost us today."
The result sees Gers slip nine points adrift of Celtic, who top the Scottish Premiership table.