Kipkorir's late surge took him over the line in 12 minutes 59.05 seconds in the city event in Zurich's Sechselautenplatz. South Sudan's Dominic Lokinyomo Lobalu (24) finished second in 12:59.40 and American Grant Fisher (25) took bronze in 13:00.56.

Earlier, Chebet claimed the women's title with a superb late charge in better conditions to make up for her silver medal at the world championships in Eugene, Oregon in July where she finished behind Ethiopia's Gudaf Tsegay (25).

Chebet, the Commonwealth champion, crossed the line in 14:31.03 to beat 2019 world silver medallist Margaret Kipkemboi (29), who was second in 14:31.52 while Tsegay clocked 14:32.11 to settle for bronze.

"It's a long season since the worlds... so it's a good performance," Chebet said. "I'm hoping that next year I come back, preparing for the Budapest world championship and hopefully be the best."

American Joe Kovacs (33) produced the third best effort in men's shot put history with 23.23m to take the crown and his compatriot and world champion Chase Ealey (28) won her first Diamond Trophy in the women's event with 20.19m.

Olympic champion Gianmarco Tamberi (30) staved off the challenge from JuVaughn Harrison (23) to defend his men's high jump title with a leap of 2.34m after Australia's Nina Kennedy (25) cleared 4.81m at the third attempt to win the women's pole vault.

The action continues on Thursday with 26 finals at the Letzigrund Stadium, including the highly-anticipated men's and women's 100m and 200m races.