Duplantis missed his first attempt at 6.11m, with Greece’s Emmanouil Karalis retiring after failing twice at the same height. The Swede then had the bar raised to try for a new record, which he successfully completed, despite rattling the bar slightly on his second effort.
After setting a new record at the second attempt on Tuesday night, Duplantis ran straight to the crowd to celebrate with his family and partner Desire Inglander.
Duplantis will compete at the Silesia Diamond League in Poland on Saturday, where he also broke the world record last year.
He will seek to become only the second man, after Sergey Bubka, to win three successive world outdoor pole vault titles when he competes in Tokyo next month.
Between 1984 and 1994, Ukraine’s Bubka broke the outdoor world record 17 times and the indoor mark 18.