Big Brother’s 20th season kickoff (1.5 demo rating, 5.29 million viewers) took every half hour of its two-hour broadcast, with a 46% edge in total viewer and 50% in the 18-49 age bracket. That said, the total viewer tally was down 6% compared to last season’ opener, marking a new series low. And the demo tally replaced last year’s 1.7 as lowest rating for a BB opening to date.

That Big Brother lead-in boosted Code Black (0.8, 5.68M) demo-wise, by 1/10th compared to previous week to equal its season high.

Fox’s 8 PM MasterChef (1.0, 3.72M) matching its best demo showing so far this summer, despite Big Brother‘s launch and a repeat of NBC’s resilient Ellen’s Game of Games (0.8, 4.20M).  After MasterChef, a 9 PM original Gordon Ramsay’s 24 Hour to Hell & Back (1.1, 3.53M) climbed back to its June 13 premiere demo number.

Following Game of Games and World of Dance repeat (0.6, 2.77M), NBC’s Reverie (0.3, 1.80M) slipped 1/10th.

CW got pre-empted in New York City, so stats are subject to more change that typical for repeats of Supergirl (0.2, 1.19M) and The Originals (0.2, 840K).

CBS (1.3, 5.417M) won the night, ahead of Fox (1.0, 3.626M); NBC (0.6, 2.922M) and ABC (0.6, 2.420M) tied for No. 3 in the demo, followed by CW (0.2, 1.018M).