Kilmarnock boss Allan Johnston described losing 5-2 at home to Celtic in the Scottish Premiership as "unbelievable".
The hosts, who trailed 3-0 early on but hit back with two goals before the break, conceded another two late goals.
"For the level of performance we produced today, to lose five goals, it's unbelievable," said the manager.
"We were dominating the game at that stage (when Celtic opened the scoring) and were passing the ball well."
Sammy Clingan and Sean Clohessy gave the hosts hope of staging a thrilling comeback at Rugby Park before late goals from Georgios Samaras and Amido Balde sealed the points.
"We make a mistake and it costs us dearly again," said Johnston. "But we've got to react better after making that mistake.
"At 3-2 we're still in the game and then we switch off at a set-piece. Young Mark O'Hara came on for Manuel Pascali because he wasn't feeling well.
"He's lost his man and it's cost us. If we play like that week in, week out then we won't be far away. That's what we have to produce.
"I'm not happy with results and we need to start picking up points."