Ndombele scored an outrageous lob to restore the visitors’ two-goal advantage, moments after David McGoldrick halved the deficit on the hour.
Serge Aurier gave Spurs the lead after five minutes, with Ndombele also involved in the build-up, and Harry Kane made it two before the interval, as Mourinho’s men returned to winning ways in the Premier League.
“A very basic mistake, very basic, gave them the goal with the only chance they had, but then we had a genius action to bring us again to a two-goal advantage," said Mourinho.
"The goal is amazing, but I don't care about the goal, I care about the performance and the performance was magnificent and I'm really pleased that he's come to this level. He's playing very, very well.”
Mourinho publicly criticised Ndombele’s attitude and fitness last season but, in a message to his out-of-favour players, added that the 24-year-old is a "great example that my door is always open”, as he completed an impressive 90 minutes in Yorkshire.
Mourinho also used Ndombele to make a point about the versatility of top players, hitting out at the entourages of unnamed players and “directors” who argue that performances are linked to certain systems or coaches.
“A top player plays in every position, and it's not a problem for a top player,” Mourinho said, when asked about Ndombele’s best role. "Top players, they don't get excuses about the system, the position, the way the team plays.
"Top players they play in every team, in every system, with every coach. When sometimes I listen 'Player x is not playing well because the team plays this way or that way', that is bull****.
“That is typical excuses from players' entourage, directors without any idea of what football is, that is just speculation. Tanguy is a midfield player.”
Ndombele was unhappy with his game-time at Spurs last season and sought a meeting with chairman Daniel Levy, who reassured him it would take time to settle in English football
Their exchange was captured in Amazon Prime Video’s fly-on-the-wall documentary of Spurs’ 2019-20 season and Mourinho admitted Levy also deserved some credit for Ndomble’s turnaround.
“Is the player’s mentality, the player’s will to train hard, the player’s will to be available for the team, the player’s desire to win, to earn a place in the team – the player is the most responsible,” Mourinho said.
"Mr Levy’s responsibility, in my opinion, is some, but is minimal compared with the player. But is true, Mr Levy believed in the player and pushed the player in some conversations they had, that the door was open for him.
“And to me it’s always the same: the door is always open, but the player cannot expect for me to go and bring him. It has to be for the player to walk through that door, and come in the direction of what the team needs from him. So total credit for Tanguy, and I think also Mr Levy deserves some.”