NBC’s new Jennifer Lopez-fronted drama “Shades of Blue” has proven to be a strong gainer in early delayed-viewing ratings, as last week’s episode — which went up against a Republican presidential debate in much of the country — saw another sizable lift.

The cop drama opened strong on Jan. 7 with a 1.8 same-day rating/6 share in adults 18-49 and 8.55 million viewers overall before falling last week to a 1.3/5 in the demo and 6.64 million viewers. In Nielsen’s “live plus-3” estimates, though, last week’s second episode spiked 72% in 18-49 rating (1.32 to 2.27), up from a 58% lift in week one (1.81 to 2.86). As a result, its week-to-week decline in L+3 was trimmed to 20%, a fairly typical decline for a show following its heavily promoted premiere.

The 18-49 percentage gain lift of 72% was the highest for any broadcast program last week (through Friday). And the raw 18-49 lift for last week’s “Shades of Blue” (0.95) is the third biggest L+3 increase this season for the second episode of a rookie season, behind only NBC’s “Blindspot” (1.60) and ABC’s “Quantico” (1.42).

In total viewers, the Jan. 14 episode of “Shades of Blue” grew by 56% (6.6 million to 10.4 million), up from 46% in week 1 (8.6 million to 12.5 million). The raw lift of 3.750 million viewers — down just 5% from a 3.961 million increase for its premiere — is the third biggest total-viewer lift ever for an NBC series premiere.

In both “same-day” and “live plus-3” ratings, “Shades of Blue” has won over its ABC and CBS competition in each of its first two weeks — no small feat considering the Peacock’s recent struggles in the Thursday-at-10 hour. Lopez has also been drawing good ratings Thursdays for Fox’s final season of “American Idol,” on which she continues to serve as a judge.