Rob Hulse opened the scoring for the visitors and appeared to set them on their way to three further promotion points, but a brace from Joe Garner and further goals from Michael O`Connor and Mark Duffy left the league leaders stunned.
"It was one of those days that sometimes happens in football," said philosophical Rangers boss Warnock.
"It was a game that we could and should have won. We were much the better team for the first half. We got an early goal and if we had got a second I am sure it would have killed Scunthorpe off. We had the chances but we failed to take them.
"We have got the best defensive record in the Championship this season and one of the best I think in the whole of the Football League. But we didn't look like that here - the goals we gave away were poor, we looked more like a raggy-arsed Rovers.
"I have no complaints about the result, we got what we deserved. But we've got to look ahead, we've got another game coming up on Tuesday and I already know the team that I'll be picking for that."
Source: PA
Source: PA