CBS entry “The Briefcase” was the best performer among the three rookie unscripted series airing on a crowded Wednesday night for reality programs. Fox veteran “MasterChef” was on the rise to lead them all in key demos, but its lead-out “Bullseye” got off to a modest start.

According to preliminary national estimates from Nielsen, “The Briefcase” averaged a 1.3 rating/5 share in adults 18-49 and 6.8 million viewers overall in the 8 o’clock hour — topping the demo scores earlier this month for the debuts of ABC’s “500 Questions” and NBC’s “The Island” (both 1.2) but below the potent 1.8 preliminary rating for the Peacock’s “I Can Do That” on Tuesday, airing behind “America’s Got Talent.” The CBS newcomer also did quite a bit better than “American Baking Competition,” which premiered to a 1.0 demo rating for the net on the comparable Wednesday two years ago.

“Briefcase” was Wednesday’s most-watched series overall, and its 6.8 million viewers tops all 10 unscripted reality premieres on the Big Four this summer and last.

Also in the 8 p.m. hour, ABC’s weeklong quizshow “100 Questions” (1.0/4 in 18-49, 4.9 million viewers overall) was a bit below Tuesday’s averages as it heads into tonight’s seventh and final night. And over at Fox, “MasterChef” (1.5/6 in 18-49, 4.6 million viewers overall) had a good night, rising 25% (0.3) above last week’s two-hour season premiere and standing as Wednesday’s No. 1 series in 18-49.

“MasterChef” led into the series premiere of “Bullseye” at 9 (1.1/4 in 18-49, 3.4 million viewers overall), with the competition series hosted by Kellan Lutz neck and neck with the repeat offerings on ABC and CBS as the hour’s No. 1 broadcast series in 18-49. “Bullseye” was the 9 p.m. hour’s outright series leader in adults 18-34 (0.8/3) and all key male demos.

ABC followed “500 Questions” with encores of comedies “Modern Family” (1.1/4 in 18-49, 4.2 million viewers overall) and “Black-ish” (1.0/3 in 18-49, 3.5 million viewers overall) and reality show “Celebrity Wife Swap” (1.1/4 in 18-49, 3.4 million viewers overall), which was up a tick from last week’s premiere. And at CBS, repeats of “Criminal Minds” (1.2/4 in 18-49, 6.6 million viewers overall) and “CSI: Cyber” (1.0/3 in 18-49, 5.7 million viewers overall) closed out the night.

NBC opened with a repeat of the previous night’s premiere of “I Can Do That” (0.7/3 in 18-49, 3.1 million viewers overall), followed by the two-hour “iHeart Radio Country Festival” special (1.0/3 in 18-49, 4.1 million viewers overall).

And CW went with encores of Wednesday drama regulars “Arrow” (0.2/1 in 18-49, 1.0 million viewers overall) and “Supernatural” (0.2/1 in 18-49, 0.7 million viewers overall).

Preliminary 18-49 averages for the night: Fox, 1.3/5; CBS, 1.2/4; ABC, 1.0/4; NBC, 0.9/3; Univision, 0.8/3; Telemundo, 0.6/2; CW, 0.2/1.

In total viewers: CBS, 6.3 million; ABC and Fox, 4.0 million; NBC, 3.8 million; Univision, 2.3 million; Telemundo, 1.4 million; CW, 0.9 million.