Update: The final Nielsen data painted an even better picture of Thursday’s “The Big Bang Theory.” The episode drew a 5.7 adults 18-49 with 20.35 million viewers.

Thursday’s “The Big Bang Theory,” the last of this season’s episodes to air without competition from “American Idol,” dominated the nightly ratings race.

Up from last week’s 5.4, this week’s 5.6 adults 18-49 rating represented the show’s best young adult performance since February 21, 2013. Its 7.5 mark in adults 25-54, meanwhile, was the best since February 7.

The show’s achievement in the viewership category was even more impressive. Thursday’s episode, which drew 20.08 million viewers, was the most-watched regularly scheduled “Big Bang Theory” to date.

Only the second part of this season’s premiere, which attracted 20.44 million viewers in its special 8:30PM timeslot, attracted a larger overall audience.

Benefiting from the strong “Big Bang Theory” lead-in and an absence of daunting competition from rival networks, CBS’ other series also performed well Thursday. “The Millers” matched its series high 3.3 adults 18-49 rating and set a new series high with 13.61 million viewers.

“The Crazy Ones” (2.4, 9.62 million), “Two and a Half Men” (2.4, 9.48 million) and “Elementary” (2.0, 9.85 million) also enjoyed week-over-week gains.