CBS has given The Big Bang Theory spin-off Young Sheldon a full-season order, the network announced Wednesday. The hasty pickup comes less than 48 hours after Young Sheldon's very successful premiere.

Young Sheldon was the most-watched comedy premiere on any network since 2 Broke Girls in 2011, pulling an audience of 17.21m viewers. It earned a 3.8 rating in the adults 18-49 demographic, the highest rating for any new comedy since The Crazy Ones in 2013. And perhaps most remarkably, it retained an astonishing 98% of its Big Bang viewer lead-in. That's the highest retention percentage of any of the myriad comedies launched in the valuable post-Big Bang slot. The Big Bang Theory's Season 11 premiere averaged a 4.1 rating in the key demo and 17.7 million viewers, according to The Hollywood Reporter.

CBS probably wishes it could air a new episode of Young Sheldon every week, but the next episode won't air until the series' Thursday timeslot premiere in early November.

Iain Armitage, <em>Young Sheldon</em>Iain Armitage, Young Sheldon

Young Sheldon stars Big Little Lies' Iain Armitage as 9-year-old Sheldon Cooper, the character played by Jim Parsons on The Big Bang Theory, and follows his trials and tribulations as a boy genius in an anti-intellectual East Texas town in 1989. It co-stars Zoe Perry and Lance Barber and is executive-produced by The Big Bang Theory's Chuck Lorre and Steven Molaro as well as Parsons and Todd Spiewak.

Young Sheldon returns Thursday, Nov. 2 at 8:30/7:30c on CBS.

(Full disclosure: TV Guide is owned by CBS.)