David Muir leads ‘ABC World News Tonight’ to 1st ratings win since ’09

Brian Williams, look out. There’s a new contender in evening news, and his name is David Muir.

ABC’s “World News Tonight,” which Muir took over as anchor from Diane Sawyer barely a month ago, is on a ratings roll. At the end of September, the newscast logged its first weekly win over Williams’ long-dominant “NBC Nightly News” since 2009, according to Nielsen.

Muir drew 8.4 million total viewers versus 8.2 million for Williams. “CBS Evening News” was a distant third with 6.6 million.

In fact, “World News Tonight” won all the major demographic categories for news ratings for the first time since 2008.

Ratings for news programs tend to change very slowly, mostly because viewers typically find a favorite anchor and then stick with that person until he or she leaves the show. So the kind of movement that Muir and his newscast have delivered inside of a month is noteworthy.

“World News Tonight’s” emergence also delivers another bad stroke for NBC News, which has in recent months struggled with ratings problems at “Today” and “Meet the Press.”

Of course, it’s still very early in the game. But for now, Muir has momentum on his side.

And Williams has reason to be concerned.

What do you think of Muir and his newscast?

Twitter: @scottcollinsLAT