Rotherham United boss Neil Redfearn says his side were uncharacteristically nervous as the Millers crashed to a 4-1 defeat to Charlton at the New York Stadium.
Charlton claimed an important three points thanks to a brace from Simon Makienok, who struck the opener on four minutes and third on 69 minutes either side of strikes from Igor Vetokele and Ademola Lookman.
Rotherham had levelled Makienok's opener with Chris Burke scoring on his home debut on 11 minutes but they missed a glorious chance at 3-1 down when Jonson Clarke-Harris smashed a penalty over the bar. Lookman then sealed the victory in added on time.
Redfearn said: "I thought we were poor today but they played well. I've got no qualms with the result.
"I thought we looked a little bit tentative and nervous in the first half and I can't understand why.
"We wanted to play backwards and square instead of forwards. They got through us too easy and that was the disappointing thing. It was unlike us.
"Today from the off I didn't think we applied ourselves. I don't want to be too critical of the players because we've had some good results lately.
"I thought at 1-1 we would go on and win it because they wobbled a little bit."
Redfearn admitted that if Clarke-Harris' penalty had gone in then it could have been a different result.
He added: "To be fair to Jonno he pushed and shoved his way in and won the penalty himself but penalties are black and white and having it saved or missing the target is frowned upon.
"It would have been interesting had it gone in to see how Charlton would have reacted.
"I'm disappointed more with the performance. We've got to run teams closer than that. We've got to pick ourselves up."