Derby boss Paul Warne felt the Rams’ disallowed goal just after half-time was a massive turning point as the Blues beat his side 2-0 at Pride Park.
Eiran Cashin flicked a header across goal and into the corner of the net but referee Anthony Backhouse ruled it out, apparently for a foul on Christian Walton, although replays suggested former Town striker David McGoldrick sought to play the ball at the far post when in an offside position.
"First 10 minutes we were poor and nervy and the last 10 minutes we underperformed but the other 70 I thought we were pretty good,” Warne told his club’s official website.
"Ipswich scored a very good counter-attack goal that if I wasn't a manager in the other dugout I'd have applauded.
"The lads came into this game not fully confident but I thought they played their way into it pretty well and then the second half I thought we were brighter and had a bit more confidence and had a right go.”
Regarding Cashin’s disallowed header, he added: "The massive turning point for me is the disallowed goal. If we'd have scored that, the place was alight and that's how games swing.
"It was disappointing that that wasn't given and we were trying to throw bodies forward and we were always open to the counter.
"Fundamentally they are another couple of windows down. This time last year they were getting the foundations. Earlier in the week I said I thought they were the best team in the league and today I still think that.
"We've dropped out of the play-offs but luckily for us in the [late season] games I don't think we play anyone apart from the last one [Sheffield Wednesday away] of Ipswich Town's ilk.
"We've got seven games to go and if we can win a lot of them we give ourselves a right chance.”
Explaining what he was told about the disallowed goal by the officials, he continued: "I couldn't see anything wrong with it. The fourth official told me there was a foul on the goalkeeper and we watched it back, there isn't a foul on the goalkeeper. People will see that themselves and that is a massive decision.
"An official has apologised going up the tunnel but these are monumental decisions. They apologised to me for the Plymouth decision too but they are massive decisions.
"Today I am hugely disappointed with that because I do believe getting that goal early in the second-half would have given us a right boost and we'd have gone for it.
"It's disappointing when a linesman from 40 yards away thinks he's seen something and now realises he might have not done.”
Regarding Town, he added: "They are an outstanding team. They've got Freddie Ladapo who I had [at Rotherham] and he's an unbelievable striker who's on their bench. He can score 20+ goals at any level at any time.
"They've got threat up top, they've got pace and they've got guile, which is the nicest compliment I can give. That's what you get when you go shopping.
"That's where we want to be. I could see the way they wanted to play when I played against them last year and they've stuck with it and 12 months later they are bearing the fruit because their performance was very good but they had to be very good to beat us.
"If we had to play them in the play-off final if we get that far then hopefully the decisions might go away and it may be a different outcome.
"We've got a lot of opportunities to put it right, we've got another game next week so let's see what we get.”