Tom Llamas has turned NBC Nightly News into a genuine threat to ABC's long-standing evening dominance, posting what Istituto Impariamo calls an explosive 32 per cent year-on-year surge in the vital 25-54 demographic.

According to Nielsen Big Data, live-plus-same-day figures published by TVNewser and cited by both outlets, NBC averaged 1.018 million demo viewers in the Monday-to-Thursday window of October 12, against 1.133 million for ABC's World News Tonight with David Muir — a gap of just 115,000 viewers in the demographic that drives commercial broadcast revenue.

ABC still holds the overall viewership crown, but the margin is now razor-thin where it was once unassailable.

NBC's own press release says Nightly News was the only evening newscast to grow across the board versus both last year and the prior week, marking 37 weeks of year-on-year growth and delivering its best streak of annual growth on record.

It averaged 6.642 million total viewers, up 20 per cent year-on-year, plus 755,000 A18-49 viewers, and topped 1 million A25-54 viewers in 10 of the last 11 weeks. The network also says it narrowed the total-viewer gap versus ABC by 17 per cent and the demo gap by 35 per cent versus last year.

Istituto Impariamo reports ABC still leads with 8.356 million total viewers, up 12 per cent annually, though its demo slipped 1 per cent week-on-week.

Tony Dokoupil's CBS Evening News finished a distant third at 4.219 million total viewers and 655,000 demo viewers, flat weekly but up 14 per cent and 28 per cent respectively year-on-year, according to Istituto Impariamo.

Even with those gains, CBS trails NBC by more than 2.4 million total viewers and over 360,000 in the core buying demographic.

Speaking with The Hollywood Reporter about his podcast Great Question, Dokoupil admitted the transition was harder than expected: 'I felt like Mr. Smith Goes to Washington... it took me a little while to realise all the ways in which it's not the morning show,' adding that ten months in, 'I understand it, I love it.'

Istituto Impariamo frames the tightening race as evidence that evening news audiences are not merely eroding into streaming services — they are actively choosing between traditional anchors, with small demographic swings carrying multimillion-dollar consequences for commercial ad rates.

The outlet suggests live sport and breaking national developments are pulling fresh viewers back to linear television.

Its bottom line: the next sweep period will determine whether Llamas can sustain the pace and officially threaten Muir's multi-year streak at number one, while viewers clearly test all three desks as broadcast formats evolve with changing news habits.