After three years in Barcelona, Fabregas returned to the Barclays Premier League on Monday night - and he instantly looked at home in Mourinho's side, who looked very much like title contenders.
The Spain midfielder set up Andre Schurrle with a perfectly-weighted pass and he also had a hand in each of Chelsea's other two goals, scored by Diego Costa and Branislav Ivanovic.
Watching the £27million signing dictate a high tempo and put in tackle after tackle, it was hard to think why Arsenal, and Manchester United in particular, passed up the opportunity to sign the 27-year-old Catalan, who was given the man of the match award for his efforts.
Afterwards Mourinho praised Fabregas for providing him with the creativity and drive that was sometimes missing from the Chelsea midfield last season.
"I think the team played very well but I agree with Cesc being the man of the match because him and (Nemanja) Matic they controlled the game," the Chelsea manager said.
"Those two dictated the intensity of the game
They are both good brains in this team and I am happy with that because probably last season we couldn't control the game the way we did today.
"In the last 10 years, Cesc and I were in the same league for six or seven years so I know what he can bring to this team.
"He makes the right decisions, the right intensity of the game and he brings other people in the right direction
I am really happy with him."
Fabregas was one of four summer signings to feature in a new-look Chelsea team now shorn of the likes of Ashley Cole and Frank Lampard.
Chelsea will come up against better opposition this term, but the way they started the season suggests this new and improved Blues team deserves its status as title favourites.
Costa was a constant menace to the Premier League newcomers all night and he got on the score sheet with a poacher's effort from 12 yards.
Fabregas then cushioned a perfect ball into the path of Schurrle to cap off a 25-pass move before Ivanovic met the Spaniard's corner to make it 3-1 in the 34th minute.
Mourinho was happy with how his team responded to Scott Arfield's opening strike, and he found Chelsea's second goal particularly pleasing.
"Everything was fantastic, the movement and the quality of the pass and the vision and the understanding between them was beautiful," the Portuguese said of Schurrle's goal.
"Emotionally we were not affected by the goal we conceded.
"We conceded a goal, but we never lost composure and we deserved these three points against a side that is going to give a fight to everyone that comes here."
Mourinho's only complaint was with the officials for booking Costa for simulation when his trailing leg was actually caught by Burnley goalkeeper Tom Heaton.
"It was a penalty, but the linesman decided not to give it," said Mourinho, who also handed Thibaut Courtois his debut and brought summer signing Didier Drogba off the bench in the second half.
"The kid (Costa) presents himself here today with a fantastic, competitive, clean and polite attitude.
"I hope he doesn't get more unfair decisions."
Burnley manager Sean Dyche, who led the Clarets back into the top-flight last term, was not too disheartened by the defeat, which came in front of a noisy capacity crowd at Turf Moor.
"Chelsea have quality in all areas," the former Watford manager said.
"We kept going, which is important
The will and demand is there.
"We have a strong mentality
Ian Holloway said last year we had the strongest jaw in the division.
"We know it is not a sprint, it is a marathon and it is going to be a tough marathon."
Dyche has brought in seven new players this summer, but he feels more additions are needed.
He said: "We need to build a squad
It is not just a starting 11
We are carrying light numbers
We definitely need strength in depth."
Source : PA
Source: PA