NBC had the best night, despite losing its strong summer series The Titan Games last week. The American Ninja Warrior repeat airing in its place drew a solid-enough 0.5, a few tenths behind how you'd expect Titan Games to perform. Behind it, the Democratic Convention was down about eight tenths from 2016 to a tepid 0.3.
CBS had comedy repeats at 0.4 and a repeat of All Rise at 0.3. Nothing deserves to air after All Rise repeats, but the Democratic National Convention did and it certainly wasn't helpful, with the hour of coverage drawing the lowest across the big 3 - a 0.2. Still, its drop from 2016 is a smaller four tenths.
ABC had a slightly better night than when they air Bachelor clip shows, with a 0.4 to kick off the night for a Holey Moley repeat. A To Tell the Truth encore at 9 was down to 0.3, and the Democratic National Convention matched that number, down six tenths from 2016's night one coverage on ABC.
Fox had 9-1-1-Verse repeats at 0.4 each.
The CW had Whose Line? repeats at 0.2 and an original Penn & Teller, also at 0.2.
Finals Update: The Democratic National Convention on NBC (+0.1) and ABC (+0.1) adjusted up. The repeat of American Ninja Warrior (-0.1) adjusted down.