Pogba set up Anthony Martial for the equaliser and scored the third goal as United came from behind to beat Newcastle 4-1 at Old Trafford.
The France midfielder had missed the past 12 league and cup games with a hamstring injury.
“It was a great performance from him,” said Mourinho.
United had failed to win three of their previous seven league games without Pogba as he recovered from injury.
However, the 24-year-old produced a man-of-the-match performance as United set a club record of 38 games unbeaten at Old Trafford to beat Newcastle and stay in touch with leaders Manchester City.
“Paul Pogba is different class – Paul and Nemanja Matic grew up together at the start of the season and are the engine of the team,” added Mourinho, who replaced Pogba after 70 minutes with Marouane Fellaini.
“It was in Paul’s hands, how many minutes to play until he began to feel fatigued. It was a great performance from him.”
On a positive day for United, striker Zlatan Ibrahimovic also marked his return to action with a 14-minute appearance as a substitute.
Ibrahimovic was making his first appearance since suffering a cruciate knee ligament injury on 20 April.
“To see him back is a great emotion,” added Mourinho. “His was such a dramatic injury.
“You recover some players and you lose others, some teams are luckier.
“We have had to go through difficult matches without important players. Let us see if we can go through the Christmas period with all the players available at our disposal.
“The more players we have, the better for me.”