Sarri's men maintained their 100 per cent start to the season in controversial fashion, a contentious Eden Hazard penalty awarded after a Fabian Schar challenge on Marcos Alonso - in which the Switzerland international seemed to make contact with the ball - giving them the lead.
That gave Chelsea a helping hand after 76 minutes of frustration, the Blues having until then failed to break down a Newcastle side set up to soak up pressure.
Newcastle responded seven minutes later, Joselu heading in a cross from DeAndre Yedlin, who appeared to elbow Olivier Giroud in the build-up.
Yet Yedlin handed Chelsea the points as he turned Alonso's first-time effort into his own net, and Sarri was able to reflect on a hard-earned win.
"The match has been very difficult, they were so compact it was impossible to have spaces, so it was really difficult," he told Sky Sports. "It was better in the second half, but a very difficult game.
"I have never seen Benitez in Italy with five defenders, so at the beginning I was really surprised."
Sarri's post-match media conference saw him quizzed on both key decisions, but the Italian insisted he was not in a position to have a definitive opinion on either incident.
Asked if he was angry at the apparent elbow from Yedlin, Sarri said: "No, I thought only it was the first time of our opponent in our box, it is impossible, was a bit unlucky, but I don't know if it was an elbow or not. I was far [away]."
On Chelsea's penalty, he added: "It is the same, I saw from far. The benches are on the line of the half, so for me it was really difficult for me to say if it was a penalty, the same for the action on the other side.
"I was about 50 or 60 metres [away], I am not able to say. I am not a referee and I don't want to be a referee ever."
Hazard's goal highlighted an impressive performance on his first start since returning from the World Cup, but Sarri did not intend to have him play the full game.
"I think he played very well. Maybe it would have been better for him in this moment to play 70 or 75 minutes, but after the first goal [Mateo] Kovacic asked me to make the substitution," Sarri explained.
"So it was the preferred [option], so it was impossible for him to rest."