The summer signing produced his best display since his arrival, causing havoc in the Everton back line as Chelsea ran out 2-0 winners over their top-four rivals.
Havertz was unlucky not to get on the scoresheet - the opening strike going down as a Ben Godfrey own goal - before winning the penalty which Jorginho scored to settle the game.
It was Havertz's first start in six weeks, having suffered further setbacks in an already injury-hit season, but feels he has turned a corner under his new manager.
"I played like a false nine, I had the freedom to go everywhere I wanted to go, and I think that’s good for me," he said.
"I like to have freedom on the pitch. I think I was lucky to score a goal but I'm very happy with the performance, not only from me but the whole group.
"I think we can do a lot better than today, but the result was a win so of course we’re very happy with it."
He added: "The first seven months were not easy for me but you have to keep working and I did that.
"So I’m very happy, but of course it was my first match after injury. I think it was a good performance from me, but you cannot say this after one performance."