Video has captured the moment Lorde and Jack Antonoff were yelled at by a pro-Israel heckler, along with their fiery response.
The pair was performing at the fourth annual all-star Ally Coalition charity show in New York when an audience member decided to loudly voice his objection to Lorde cancelling a concert in Tel Aviv.
"You guys are so nice, I wish all shows I played at were this nice," Lorde gushed in between songs.
"In Israel they're also nice," yelled the unknown man.
"I know, I know that," responded Lorde - but Antonoff leapt to her defence.
"Oh come on," he said, standing up from his seat.
"We've raised a shit-ton of money tonight. F**k that negativity."
He and Lorde patted each other on the back as the audience cheered.
"You know where they're nice? Right here! Right f**king here," continued Antonoff.
"That motherf***er better donate a couple, $10,000 more to this shit," he continued.
"I appreciate it. Thank you so much," added Lorde.
The emergence of the video comes after Antonoff shot down rumours he and the Kiwi songstress were dating, which flared up after he and TV star Lena Dunham split up.
Lorde announcing her first ever concert in Israel last month, then cancelling it some days later, has been widely talked about internationally.
She's been praised by the likes of Roger Waters for "standing up for the Palestinian people", and criticised as a "bigot" by others including Roseanne Barr and Howard Stern.