The midfielder, who joined The Black and Greens from German side Eintracht Frankfurt last month, was deployed in the unusual striker's role as Sassuolo sealed a 1-0 home triumph at Mapei Stadium - Citta del Tricolore.
Domenico Berardi scored the decisive goal from a penalty in the 27th minute.
"I stole the idea [playing Boateng as a No.9] from when he was at Las Palmas, a team that I very nearly went to work for," De Zerbi told Sky.
"It’s very helpful, especially at the start of the season, to have a player in attack who can find his way out of pressing.
“The way Boateng attacks the space makes him a real No.9, not a false nine. We try to push the moves more down the flanks with Federico Di Francesco and Domenico Berardi."
Boateng, who was a handful for Inter's defence, came close to grabbing an all-important debut goal when his first-time effort came against the foot of the upright.
He was replaced five minutes to full-time by Senegal striker Khouma Babacar.
“Boateng is also very important in the locker room," De Zerbi added.
"He is always positive and enthusiastic, but also very helpful for some players who just arrived and can’t speak Italian yet.
"If they need help communicating in English, German, French or Spanish, he’s always on hand to make them feel more comfortable.”
Boateng is not anyway new to Serie A, having had two separate stints with AC Milan.