Young Sheldon has gotten a very fast vote of confidence.

Two days after its series premiere, CBS has handed out a full-season order to the Big Bang Theory prequel. The Warner Bros. Television single-camera comedy will now have a total of 22 episodes.

From executive producers Chuck Lorre, Steve Molaro and Emmy winner Jim Parsons (who narrates), the 1989-set comedy starring Iain Armitage as a 9-year-old Sheldon Cooper launched Monday after the flagship show to become the most-watched series premiere in any network since 2011. Airing after the season 11 premiere of The Big Bang Theory, Young Sheldon averaged a whopping 17.2 million viewers and an impressive 3.8 among the advertiser-coveted adults 18-49 demographic. The series retained 98 percent of its Big Bang lead-in among total viewers and 93 percent in the demo. That's the best post-Big Bang performance for any new comedy in the slot and provides the network with a reliable performer behind TV's No. 1 comedy in the demo.

Following its Monday sampling, Young Sheldon — which stars Zoe Perry as Sheldon's mother, Mary, taking on the role played by her mother, Laurie Metcalf, on Big Bang — moves to Thursdays at 8:30 p.m. when the flagship takes over the night's 8 p.m. slot on Nov. 2.

Young Sheldon is the first new show from the 2017-18 broadcast season to score a full-season pickup. It comes as no surprise after CBS focused the bulk of its fall marketing campaign on the Big Bang prequel. The series, which opened the season with instant brand recognition, was met with mixed reviews from critics.

Parsons — who has an overall deal with Warner Bros. TV — came up with the idea for the new series and took it to Big Bang co-creator Lorre and showrunner Molaro. CBS Corp. CEO Leslie Moonves gave it a straight-to-series order. With the pickup, Lorre will have three full-season shows on CBS this year: Big Bang, Young Sheldon and Mom, as well as a pair of shows on Netflix.