Last week’s “Jimmy Kimmel Live” on the night of the big “Scandal” season finale has set a series record for the 11-year-old  ABC latenight show.

Nielsen estimates that an average audience of 4.028 million watched Thursday’s episode, dubbed “Behind the Scandalabra” and featuring a discussion of the hit ABC show and its finale with creator Shonda Rhimes and some cast members. In adults 18-49, its 1.425 million on Thursday was also the highest ever for a latenight telecast of “Jimmy Kimmel.”

And for the week, despite airing four repeats in addition to the big Thursday episode, “Kimmel” hit a five-month high in total viewers (2.84 million).

NBC’s “Tonight Show Starring Jimmy Fallon” still won last week’s latenight ratings race, with its full week of encores averaging 3.069 million, while CBS’ “Late Show With David Letterman” week of repeats averaged 2.724 million. In adults 18-49, “Tonight” won easily with a 0.94 rating, followed by “Jimmy Kimmel” (0.71) and “Late Show” (0.54).

This is the highest-rated week of “Tonight Show” encores in nearly three years (since May 30-June 3, 2011 with Jay Leno as host), up 19% from the comparable repeat-filled week of a year ago.

Of note in latenight this week, Tuesday’s edition of CBS’ “Late Show With David Letterman” — featuring a visit from Letterman’s eventual successor, Stephen Colbert — scored a rare household victory over NBC’s “Tonight Show” in Nielsen’s metered-market overnights (2.5 to 2.3), with ABC’s “Jimmy Kimmel Live” third (1.7).

And Letterman was a bit more competitive in demos, earning a second-place tie with Kimmel (0.5 rating) in the 25 markets where data was available; Fallon finished on top with a 0.9.