But today's competition, which Duplantis skipped the European indoor championships earlier this month to focus on, was not a simple as he often makes it look.
"It took a lot out of me, for sure. I wouldn't say I was my sharpest today, either," he told the BBC shortly after the competition.
"I felt a little bit sloppy on the runway - a little bit tired, a little bit heavy, honestly. But I had to fight really hard because Karalis jumped so well, and he pushed me like crazy."
Emmanouil Karalis of Greece claimed silver with a new national record of 6.05m, and had put Duplantis under pressure by skipping the 6.10m height, which the Swede failed at on his first attempt.
Of Karalis, Duplantis said, "The highest loser ever in the history of pole vaulting. I guess that is a testament to the level of the competition today."
When asked how he coped with the pressures of being pushed by other competitors, the 11-time world record holder was in two minds.
"I guess it depends. A few years ago I was definitely used to it all the time, having those kind of tough competitions. I guess fortunately, recently I've been jumping well and create a little bit of margin, but today was tough and Emmanouil jumped really well and he was pushing me like crazy."
"And I think that's just the kind of shape that he's in right now and I think we're going to see some crazy competitions in the future, too."
As for today, the 25-year-old put Sweden on the medal table with his 11th senior title at world or European level.
Askag's 14.01m not enough for medal
Elsewhere for Sweden today in Nanjing, Maja Askag jumped a best of 14.01m in the women's triple jump final, which was only good enough for fifth place. Emilia Sjostrand, recording 13.55m, finished in 11th place.
Julia Henriksson finished seventh in the first Semi-Final of the women's 60 metres and thus did not advance to the Final, and Wilma Nielsen failed to advance from the heats in the women's 800 metres.