Slot became the first manager since Graeme Souness in 1991 to win on his Premier League debut.
On his Quansah change, the Dutchman explained: “It wasn’t so much that we lost the ball too much, but we lost far too many duels.
“They (Ipswich) were very aggressive which led to three yellow cards, but in a good way aggressive.
“We didn’t cope with that well enough. That’s what I said to them at half-time – if you want to win here, you need to go a step up in terms of winning your duels first and make a fight out of it instead of accepting that every time we play a ball long, the ball ends up in our 16 again.
“It helped that Ibou Konate came in, he from the start won his duels from the (Ipswich) number nine and that gave us a lot of ball possession. We got two goals and could have scored more.”
Slot added: “We as a team made a big change at half-time as we came out totally different to the first half."