An estimated 67.1 million television viewers tuned in to the first debate between United States Vice President Kamala Harris and former President Donald Trump, media research firm Nielsen has announced.

Tuesday’s debate, hosted by ABC News, saw the Democratic and Republican nominees come face-to-face for the first time in a high-stakes confrontation on issues ranging from the economy to immigration and abortion.

The viewing figures mark a big jump from the estimated 51 million people who tuned in for June’s debate between Trump and President Joe Biden, but fall short of the record 84 million viewers who watched the Republican’s first debate with Hillary Clinton in 2016.

TV viewers aged 55 and older made up the majority of the audience, accounting for 41.3 million of those who tuned in, according to the Nielsen data released on Wednesday.

People aged 35-54 made up 16.9 million viewers, while those aged 18-34 accounted for 6.5 million.

By way of comparison, the series finales of popular US sitcoms Seinfeld and Friends attracted 76.3 million and 52.5 million viewers, respectively.

The Nielsen figures only refer to television viewers, excluding those who watched the debate on social media and streaming platforms.

Harris is widely seen as having won Tuesday’s debate.

In a CNN flash poll, 63 percent of viewers said Harris outperformed Trump, compared with 37 percent who said the Republican had a better night.