Even as the rave reviews were flowing in via social media, “The Wiz Live” producers Craig Zadan and Neil Meron were still sweating out the key moment they felt would make or break the production: Star Shanice Williams had to nail the final song of the night, the soaring ballad “Home.”

“Having the show end on that emotional beat and to wrap everything up with the deepness that it demands — that’s what I was worried about,” Meron told Variety. “Will she hit the notes? Will she get the emotion of it just right? That song was the moment that had to work to make the show a success.”

By all accounts, they needn’t have worried. NBC’s live broadcast Thursday of the beloved musical generated big ratings for the network and a tornado of tweets and social media activity, most of it overwhelming laudatory.

On Friday morning, Zadan and Meron were still recovering from the adrenaline rush of their one-night-only TV musical — the third that they have shepherded for NBC in as many years.

The veteran producers have worked on scores of theater, film and TV productions, but never have they had such an emotional experience with a cast and crew as they did with “The Wiz.”

“Every single person on the production had tears in their eyes when we finished,” Zadan said. “Usually at the after-party, Neil and I go around and thank all of the actors for their work. This time, all of the actors came up to us to thank us and tell it what it meant to them to be a part of this.”

The original 1975 Broadway production was a pioneering work for African-Americans in theater. Most of the key cast and many production team members had strong emotional connections to the musical and the 1979 film starring Diana Ross and Michael Jackson (which was markedly different in its story from the stage play). The reverence for that legacy sent the entire company on a mission to make NBC’s rendition in 2015 nothing less than a smash.

The A-list assemblage included prominent, racially diverse talents in director Kenny Leon, choreographer Fatima Robinson, costume designer Paul Tazewell, music producer Harvey Mason Jr., among others. The predominantly black cast was led by Williams, a discovery from an open casting call, Queen Latifah, Ne-Yo, Elijah Kelley, David Alan Grier, Common, Mary J. Blige, Amber Riley and Uzo Aduba.

“It was a mission for the creative team on so many levels for this to work,” Meron said. “We all knew how important it was to put out the message that ‘The Wiz’s’ legacy would endure for a new generation.”

Zadan and Meron and NBC settled on “Wiz” as the 2015 holiday musical more than a year ago, before last year’s production of “Peter Pan Live” aired. Zadan and Meron had tried a few years ago to get a Broadway revival off the ground with Leon at the helm.

The timing of “Wiz” coming to primetime with such fanfare was also significant. There is renewed focus in the entertainment industry about diversity at all levels of the business. And in the broader culture, it is undeniably a time of great tension about race relations sparked by an alarming string of deaths of black men by police.

“When you see all the horrible things that are going on in the world — you can’t help but want to have something that’s not depressing and not tragic. Something where there is just pure joy,” Zadan said. “The performers all attached themselves to that idea. They were so excited about doing something where nobody gets shot, nobody gets hurt. It’s just pure love and joy. They felt it every day on the set. We’ve never worked with a cast in our lives that was so emotional from start to finish.”

Zadan cited Blige as a prime example. The music vet knocked it out of the park in her role as the Wicked Witch of the West — surprising the producers and Leon with the zeal she brought to her performance. “She told me last night that she went further with this than she’s ever gone with a performance because she knew she had to give everything,” Zadan said.

Of course, nobody had more to gain or lose from the reception for “The Wiz” than Williams, the 19-year-old New Jersey native who came to the project with limited school and community theater experience. By the time she finished her final song on Thursday, everyone on the set knew that her life would probably never be the same.

“She’s sort of in a state of shock right now,” Zadan said of Williams. “We told her (on Thursday), you’re going into this with people saying ‘Who’s that?’ and tomorrow morning when you wake up everybody is going to know who you are.”

Meron said the most impressive part of her triumph in the role was that she came into it with real chops, despite her previous lack of time on stage. “From day one, she really didn’t skip any beats. She put her nerves away and did the work. Her learning curve with the camera was just tremendous,” he said. “It was supernatural,” he said.

Zadan added the most important coaching Williams needed was the discipline to not blow out her voice in every rehearsal. “It’s one thing to sing a song really well and it’s another to blow it out for 12 hours of rehearsal,” Zadan said. “We really wanted to protect her. She’s such a worker, she never thought of giving anything less than all she had.”

“Wiz Live” was a much more technically elaborate production than the previous two NBC musicals. Zadan and Meron credited their experience as exec producer of ABC’s Academy Awards telecast for the past three years with introducing them to the LED rear-projection technology that made “Wiz” so visually distinctive.

NBC and others were nervous about how it would work during a nearly three-hour live telecast. But ultimately they backed the duo’s assertion that it was the right choice. The combination of set design by Derek McLane — a longtime collaborator with Zadan and Meron — and the visuals developed by Lee Lodge for the LED backdrops allowed them to give the show a bolder look than they could have with traditional sets.

The use of that technology added a layer of expense to the production that would have tested the commitment of many companies, Zadan and Meron noted. But the pair said the level of support and encouragement from NBC, starting with entertainment chairman Bob Greenblatt, has never wavered.

NBCUniversal CEO Steve Burke and Comcast chairman-CEO Brian Roberts sent a steady stream of congratulatory emails while Zadan, Meron and Greenblatt were sitting in the production truck on Thursday night. (Yes, the trio are already planning a project for next year’s holiday season but no, they haven’t settled on a property yet.)

“They’re proud of this being a tradition for NBC,” Zadan said. “Their support for these live musicals has been unreal.”

(Pictured: Craig Zadan, Neil Meron, Queen Latifah and Bob Greenblatt)