By Lynette Rice
Updated April 14, 2010 at 04:53 PM EDT

Image Credit: Michael Yarish/FoxAll the hype surrounding the return of Glee had a big impact on the show’s ratings: the Fox dramedy earned an impressive 5.7 rating/15 share among adults 18-49 last night and attracted 13.6 million viewers, according to preliminary returns. Though the musical series didn’t air in its regular time period — it actually ran from 9:28 to 10:30 p.m. — the show’s 18-49 demos were up 46 percent over its previous series high on May 19, when the Ryan Murphy-created show debuted after American Idol. (It also gained an additional 4 million viewers during the same period). Glee also built upon its Idol lead-in last night among adults 18-34 (a 5.8 versus a 5.6).

“Everybody thought Fox was crazy to have the Sectionals in December and then pull it off the air for four months,” says Murphy, who spoke to EW exclusively. “They got a lot of criticism for it, but (the ratings) prove that it was a great plan. It really worked. In those four months we won the Golden Globe and a Peabody, and with the Oprah/White House effect, it became a perfect storm to get people really excited about the show.”

American Idol was still the dominant force on Tuesday; it finished with a 7.2/20 among 18-49 and easily won the night in the key demographic. Fox certainly benefited from the lack of originals on CBS’s sturdy schedule of NCIS, NCIS:LA and The Good Wife — all of which were in repeats last night. Still, Glee made big gains in the timeslot versus the same time last year when Fringe aired. Fox was up 43 percent from 9 to 10 p.m., thanks to all the fans who were eager to see Sue Sylvester and Co. again.

Even Murphy started to question whether the show was getting too much attention in the weeks leading up to the premiere. “I was like, enough,” he told EW. “You should see all the stuff I turn down and the cast turns down. We really try not to over-expose it but at a certain point it takes on a life of its own and there’s nothing you can do.” – With additional reporting from Michael Ausiello