Italian Olympic champion Gianmarco Tamberi saw off the challenge of American multi-discipline prodigy JuVaughn Harrison to claim the Diamond League high-jump title in Zurich.
Tamberi was expected to duel it out with Mutaz Essa Barshim, with whom he famously shared Tokyo gold.
But the Qatari was well out of sorts, only managing to clear 2.18m.
Instead Harrison, who also competes in long jump, only came second to Tamberi on countback after both cleared 2.34m.
Both men recorded season-best efforts at the specially constructed city-centre street venue that hosts the opening evening before the action moves to the Letzigrund Stadium on Thursday.
Tamberi offered a consoling chest bump to 23-year-old Harrison before grabbing his trophy and hoisting it aloft to the acclaim of the Swiss crowd.
Earlier in the evening, Kenya’s Beatrice Chebet, who won silver in Oregon earlier this summer, took a small measure of revenge on world champion Gudaf Tsegay.
On a three-lane track, whose banked turns twist round Zurich’s landmarks, Chebet held off Tsegay and Dutch Olympic champion Sifan Hassan with a well-timed kick.
Amy-Eloise Markovc, the only Briton competing on the opening day of action, finished down in eighth.
American Joe Kovacs threw a huge personal-best 23.23m to beat compatriot and world and Olympic champion Ryan Crouser in a superb shot-put contest. Kovacs moves up from joint fourth on the all-time list to second, overtaking US great Randy Barnes.
Australia’s world bronze medallist Nina Kennedy edged out United States rival Sandi Morris in the pole vault with a best of 4.81m.
In the final event of the night, Kenya’s Nicholas Kipkorir took 5,000m victory with Ethiopia’s defending champion Berihu Aregawi down in fifth and none of Selemon Barega, Yomif Kejelcha or Jacob Krop able to contend after a long season.