In its finale, the "American Idol" became a must-watch TV show. The show's last performance was viewed by more than 13.3 million people - the biggest audience it captured since February 2014, according to Nielsen data which Fox cited.

Former Idol contestants and now stars on their own right such as Jennifer Hudson and Carrie Underwood together with the original judges of the show, Simon Cowell, Randy Jackson and Paula Abdul graced the evening's farewell performance.

After the last vote was counted, Trent Harmon was declared the winner of the show's final contest. He beat La'Porsha Renae in what some observers said was an upset.

After some three years of sluggish ratings, top honchos at Fox decided to ax the series. The changes in the judges' roster and increased production costs were rumored to be part of the decision to cut it.

Before its last performance, the series was only able to garner 8.9 million viewers per night. That's peanuts compared to the 31 million viewers that watched the show in its peak.

There will be more accurate numbers after all the figures are tallied. But for now, the 126-minute TV extravaganza averaged a 3.0 rating/10 share in adults aged 18 to 49, and 12.9 million viewers in total starting from 8 p.m. to 10 p.m., the time of the show.

Of all its previous telecasts, this grand farewell performance of the "American Idol" could be counted as the series' most-viewed since its season 13. That premiere show attracted 15.2 million viewers. A few other episodes also topped 13 million.

The show featured a number of Idol alumnus aside from Underwood and Hudson. There was a WGWG (white guys with guitars) segment which featured Idol winners such as David, Cook, Lee DeWyze, Philip Philips, Kris Allen and Nidk Fradiani.

All in all, the finale was a great show. But it may come back since its creator, Simon Fuller, told The Hollywood Reporter that the show "will be coming back for sure."