Ellis Harrison put Ipswich Town ahead after 38 minutes before Billy Sharp levelled for the Blades.
The result was manager Chris Wilder’s side drop a place from fifth to sixth, with Middlesbrough moving ahead of them, while the hosts remain rooted to the bottom of the Championship table, four points from safety.
Knill said: “I thought we dominated the game from start to finish. We had a dodgy five, six minutes after they scored, but apart from that I thought that we were pretty much in control really. The only thing that was missing was a clinical finish at the end of it.
“Thankfully Billy (Sharp) was on the end of a great ball to get us back in the game at one-all.
“To be honest I thought that we were going to win the game from there, but it wasn’t to be.
“(Sharp) keeps going. He’s not disappointed when he doesn’t score and he gets into those areas where he can score.
“ I thought we were the dominant team in the first half and we’ve got a great bunch of players who want to win.
“It was a great goal and a great cross. It’s a right tough league and now is the challenge to say up there.”
Ipswich manager Paul Lambert praised his team for their battling performance.
Lambert said: “They (Sheffield) are as good a team I’ve seen so far in the short time that I have been here. All credit to my own team. We are a really young side with so much inexperience. I’m delighted with their application and the enthusiasm.
“We try to play a game against a really good side and towards the end it could have gone either way, but credit to them, they are a good side.
“It was a huge point for us. If you look at our team – Dozzell, Lankester, Downes, Chalobah – 18- to 19-year-olds. I’d love to know if there’s another team in the division with that amount of players at that age.
“The midfield is so inexperienced it’s not true.
“Dozzell shows great desire. Chlaobah is going to be an exceptional player. We are getting there slowly but surely.”
Ipswich Town: Gerken, Spence, Chambers, Pennington, Knudsen, Chalobah, Edwards, Nolan, Dozzell (Ward 69), Sears, Harrison (Roberts 78). Unused substitutes: Jackson, Nsiala, Kenlock, Bialkowski, Lankester.
Sheffield United: Henderson, Basham, Egan, O’Connell, Baldock, Norwood, Fleck, Stevens, Duffy, Sharp, McGoldrick (Clarke 69). Unused substitutes: Coutts, Stearman, Johnson, Moore, Cranie, Washington.
Referee: Andy Woolmer (Northants).