Town manager Joe Royle rued his side missing chances as they lost 2-1 to Nottingham Forest at Portman Road.
Royle said: "We had more than 20 attempts at goal but we hit the post and missed countless chances.
"I had the feeling that this match could be the trickiest of our final three. Forest at full strength are one of the better sides in the division. They proved that today.
"They were dangerous on the break when we were stretched and chasing the game. We were generally on top but couldn't force a goal when we needed it.
"David Johnson took both his goals superbly. He came back to haunt us but, apart from his goals, did not have an awful lot to do.
"We are still in the position of knowing that we will be in the play-off if we win our final two matches. I'd have settled for that position a few weeks ago."
Royle changed from the Blues' more regular 4-4-2 to a 3-5-2 due to Tommy Miller's unavailablility through a hamstring problem: "We had no obvious replacement."
Jim Magilton went off with a leg injury in the 74th minute but is unlikely to miss out next weekend: "He has stud marks on his thigh but it's not serious and he should be OK for our trip to Sheffield United next Friday evening.
"We are determined to get the job done next week."
Forest boss Joe Kinear says the result assures his side of Division One football next season: "Now the pressure about avoiding relegation is over and I can enjoy a weekend.
"It was a brilliant performance. We came with a game plan to go out and play. The pitch lent itself to producing good football. We created chances and David Johnson came up trumps.
"It is great to have him back. He has the nous for goal and knows how to finish and he's brave. He's not yet as sharp as he could be, but he will be.
"Our two central defenders, Michael Dawson and Wes Morgan, were magnificent. In the second half we were forced to defend deep to withstand an aerial attack after Shefki Kuqi was introduced to the Ipswich attack.
"It's mission accomplished. It was always the target to avoid the drop when I was appointed.
"We were aiming for 50 points but found that was not enough. The goalposts change every week and it's a great relief that we've done it."
Kinnear hopes to sign former Town loanee Paul Gerrard permanently over the summer: "He is out of contract at the end of the season but I understand one or two clubs are sniffing around.
"I'd like to keep him but cannot afford his salary. Maybe we can offer something similar over a longer period."