On a dramatic Saturday night of play-off football, goals from Takayuki Morimoto, Habib Al Fardan and Leo Lima's late penalty helped Al Nasr edge their visitors from Uzbekistan 3-2 and reach the next phase of Asia's premier club tournament.
Although strikes from Lokomotiv's Viktor Karpenko and Akmal Homatov ensured Al Nasr's success was far from routine, Zenga was adamant that his charges' victory was richly deserved.
"The match was hard for both teams," Zenga told the Asian Football Confederation's official website.
"I was so happy with the reaction of the players who managed to make a good comeback after trailing 2-1.
"We knew the strengths and weaknesses of our opponents throughout the match and I'm happy that we qualified to the group stage because we deserve to be there," he concluded.
Al Nasr, one of four sides from the UAE now set to compete in the group stages, will meet 2012 runner-up Al Ahli from Saudi Arabia, Iran's Sepahan and Qatar's Al Gharafa in Group C.
They will play away at Sepahan in their opening fixture on February 27.