Nottingham Forest's 3-1 defeat away against Reading is "a shot across the bows" for their Championship promotion ambitions, says manager Mark Warburton.
The Reds trailed 1-0 at half-time but Warburton said they were far better after the break, despite conceding two more goals before scoring late on.
"We were really poor in the first half. We didn't show any intensity and were loose," he told BBC Radio Nottingham.
"There is no lack of effort but we gave them too much time, respect and space."
Forest are still only two points adrift of the play-off places, but Warburton said his side had enough chances to have secured a win which would have taken them into the top six.
Warburton's side had 15 shots, compared to Reading's 11, and also had 57% possession.
He added: "In the second half we stepped on, played our normal football and denied them space. We showed a much better intensity and quality on the ball.
"But we didn't take our chances. To create that many chances and not take them is frustrating to say the least.
"The first half wasn't us - we didn't make it difficult for them. It wasn't about the shape, it was about stepping on.
"That first half is the shot across the bows that we need. The first half wasn't good enough and we have to recognise that."