After winning with a clearance of 2.31 metres, Kerr added two centimetres to his personal best in clearing a world-leading 2.36m in Glasgow in a huge boost ahead of the Paris Olympics.
Kerr's win made him the third New Zealander to claim a world indoor title after shot putters Valerie Adams and Tom Walsh.
A bronze medallist at the 2022 event in Belgrade and the reigning Commonwealth Games champion, Kerr has ample big-event experience but he said nerves got to him in Glasgow.
"I wasn't calm and relaxed," he told New Zealand media.
"I knew I needed to focus on myself today and in a sport where there are so many other things going on the only thing I can control is my emotion and technical queues.
"So as the competition progressed it got harder to focus on that as the outcome became more and more important ... So I did go to the bathroom a few times to just sit there and do a bit of breathing work and bring myself back to the present."
Kerr, who finished ahead of American Shelby McEwen and South Korea's bronze medallist Woo Sang-hyeok, failed to clear 2.34m and missed his first attempt at 2.36m after raising the bar but floated over on his second effort.
"It's just a great sign of things to come, the work we've been doing in New Zealand and the approach we've taken to this season is really working," he said.
"But at the same time I know going into the Olympics there are some big boys who are doing some pretty good training and some good stuff behind closed doors and so it's going to be a good challenge and something I can't wait to get amongst."
Geordie Beamish later capped New Zealand's most successful indoor world meet by winning a surprise gold in the men’s 1,500m courtesy of a big final lap.
With silvers for shot putter Walsh and pole vaulter Eliza McCartney, New Zealand took a record four medals from Glasgow, one better than their haul at the 2016 event in Portland, Oregon.
