Lorde is continuing her rise to global stardom, retaining her place at the top of the US singles charts and performing on one of the world's most popular chat shows.
The Kiwi singer extended her lead over Katy Perry's Roar to stay atop the Billboard Hot 100 for a second straight week.
Royals was 19 per cent bigger than Roar, based on a measure of digital sales, radio play and online streaming, Billboard said.
It was less than one per cent ahead when it rose to the top of the chart last week.
Lorde is also in the hunt for a US number one album.