Romelu Lukaku and Lautaro Martinez struck for the 2-1 win as Inter went 11 points clear at the top of the table.
“We needed to take another step up if we wanted to have a season as real protagonists and challenge for the Scudetto," Conte told DAZN.
“We had to become more determined, more focused in every situation, as well as more resilient. There are games like today where we can be up against teams with no pressure and if we are more clinical, we can score five or six goals. Sassuolo kept it open to the end, even if they scored only when Milan Skriniar was off the field.
“I congratulate Sassuolo, as they came here to play their game and this performance shows how much we've grown. With this attitude, we'd still be in the Champions League.
“Sassuolo make possession their main strength, so we chose to close the gaps in the centre more than anything else. We knew that we'd have to cede possession.
“Aesthetics are fine, but the Scudetto is too important. We played beautiful football in the Champions League and all anyone said was that we were eliminated, so we have to focus on the results now.
“We are trying to press high, without running too many risks, so we can make the most of players like Lukaku, Lautaro and Hakimi who can hurt teams when running into space."