Dele Alli was in scintillating touch as Tottenham secured a 4-0 win over Austrian side Wolfsberger in north London.
The English attacking midfielder has featured sporadically this season but shone when given the chance on Wednesday.
Spurs were already in control after claiming a 4-1 win in the first leg of the Europa League last-32 tie.
And Alli put any chances of a comeback to bed with a spectacular bicycle kick with 10 minutes on the clock.
Alli then delivered a smart cross for Carlos Vinicius to make it 2-0, before setting up substitute Gareth Bale to smash home a third.
16-year-old Dane Scarlett was brought on with less than minutes remaining and made an immediate impact by setting up Vinicius for his second of the game.
Speaking after the game, Mourinho was effusive in his praise of Alli and his performance.
He told reporters: "The goal I don't need to speak, because everyone watched it and I believe that all around the world on all these sports TV, people are going to watch it, no need to talk about it. but for me the globality of the performance is what matters. He played very well in every aspect of the game, he played very well.
"Of course he's not fresh, of course you can feel that his performance like in the first leg from minute 55-60 is going always to go down, which is normal due to the circumstances, injured, not training for a long time, coming from a couple of weeks.
"But in this moment when we are going to play every three days, 10 matches in March, to have Dele back at this level, is amazing. But I wouldn't say Dele only. Winks, Sissoko, just to give two more examples, to have them back to this level, we need more than ever."