This undated image released by ABC shows anchor David Muir on the set of “World News Tonight with David Muir,” in New York. After five years at “World News Tonight,” Muir has a milestone that’s increasingly rare in television. His average audience is actually larger than it used be. ABC is finishing the TV season with its largest lead over NBC in 23 years, and 27 years for CBS. It’s the third straight year ABC has won the ratings competition.(Ida Mae Astute/ABC via AP)

NEW YORK (AP) — David Muir is celebrating his fifth anniversary as “World News Tonight” anchor with something that’s rare in television: a larger audience.

The ABC newscast finished its year-long season last week with an average of 8.6 million viewers a night, the Nielsen company said. It’s the third straight year ABC has won the evening news ratings competition, with its largest margin over NBC in 23 years and CBS in 27 years, the network said.

“World News Tonight” was averaging 7.9 million viewers when Muir replaced Diane Sawyer as anchor of ABC’s flagship newscast in September 2014. At the time, NBC’s “Nightly News” was the most popular newscast behind anchor Brian Williams, who was replaced by Lester Holt in 2015 after Williams was found to have made false claims about reporting in Iraq.

“David Muir has a unique ability to connect with the American audience,” said Almin Karamehmedovic, executive producer of “World News Tonight.” ″He’s passionate and he’s fearless and he delivers the stories in a way that really resonates.”

ABC saw something in Muir and its decision to have him replace Sawyer turned out to be a good one, said Andrew Tyndall, an independent consultant who studies evening newscasts.

ABC also made “World News Tonight” a much faster-paced broadcast that is similar in tone to the local newscasts that usually precede it on ABC’s schedule, Tyndall said.

The ABC newscast’s average audience of 8.61 million is slightly down from last year’s average of 8.64 million, Nielsen said. “Nightly News” has slipped from 8.16 million viewers each night to 7.95 million. The “CBS Evening News,” where Norah O’Donnell took over as anchor in July, saw its nightly average decline from 6.22 million to 5.84 million.

On the last week of the summer TV season, NBC won bragging rights in prime time entertainment with an average viewership of 6.2 million. CBS had 5.6 million, ABC had 3.8 million, Fox had 3 million, ION Television h ad 1.31 million, Univision had 1.26 million, Telemundo had 1.1 million and the CW had 540,000.

Fox News Channel was the week’s most popular cable network, averaging 2.43 million viewers in prime time. ESPN had 1.91 million, MSNBC had 1.71 million, Hallmark had 1.38 million and HGTV had 1.33 million.