The Premier League side put in a ruthless display against an Espanyol side that are sat rock bottom of the La Liga table and have done remarkably well to reach this stage of the European competition.
Diogo Jota scored a hat-trick for the second consecutive Europa League match and Ruben Neves hit a stunning long-range volley to put Wolves in a commanding position going into the second leg next Thursday night.
Nuno was full of praise for his side's efforts at Molineux but the Portuguese tactician is adamant there is still work to be done in the second leg as they bid to reach the last-16 of the competition.
"The tie is not over," he added. "Football is never over. We competed well, the result is the consequences of what we did.
"We were clinical and that's what we want. It's another clean sheet, defensively we did really well and everything starts from there."
Nuno also reserved special praise for Jota, who became the first player since Klaas-Jan Huntelaar for Schalke in 2012 to register back-to-back hat-tricks in this competition.
"I'm happy for him, delighted because when a player scores three goals it means he has helped a lot," Nuno added. "He did a good job, not only offensively but covering and was always organised. Neves also scored a beautiful goal."
In their bid to challenge for an unprecedented Champions League place, Wolves will be looking to avoid a banana skin on Sunday when they welcome rock-bottom Norwich City to Molineux in the Premier League.
Wolves sit in eighth place in the standings after the first 26 games, with currently five points between themselves and fourth-placed Chelsea.