After an even start to the game, Forest scored three goals in six minutes at the end of the first half - Nikola Milenkovic netting after a poorly defended set-piece, Anthony Elanga arrowing in after a rapid counter-attack and then profiting after simple long ball was not dealt with.
"We got this moment right," said Espirito Santo, reflecting on that game-defining spell. "Ipswich were unbalanced and we took advantage of it.
“I think overall it was a good performance. I think we started well, organised. Ipswich is a tough team, especially in the first 15 minutes. This is a team that scores the most (early on).
“So that was a side of the plan to try to contain and sustain the impetus of Ipswich. I think we managed that.
“There’s a good spell in the first half that really changed the game, for six minutes."
Jens Cajuste and George Hirst both scored top quality goals for Town in the latter stages of the game, a top corner finish from the edge of the box and an expert leaping header, but they were sandwiched by a killer breakaway fourth from Forest sub Jota Silva.
It's the third time this season the East Midlands side have got the better of the Blues following a 1-0 win in the reverse league fixture and an FA Cup fifth round victory at The City Ground on penalties.
"Ipswich were always going to react because they are a good team," said Espirito Santo. "They have character, they're intense. It was tough.
“In the second half, we started well. There was a moment when Ipswich scored that the team shakes a little bit, but fortunately and luckily we scored the fourth goal that really protects the game.
"It was important for us that we got the fourth goal to really put the game to bed."
Forest remain third in the Premier League table going into the final international break of the campaign. They also have an FA Cup quarter-final at Brighton to look forward to.