Christian Coleman and Shericka Jackson upset the reigning 100m world champions to become this year's Diamond League trophy winners in Eugene, Oregon.
Coleman, 27, beat fellow American Noah Lyles to win the men's title, equalling the world-leading time of 9.83 seconds.
Sha'Carri Richardson then had to settle for fourth as Jamaica's Jackson, 29, won the women's 100m.
Britain's Laura Muir was denied a third Diamond League title after a superb run by Faith Kipyegon in the women's 1500m.
Norway's long-distance star Jakob Ingebrigtsen won the men's mile as he ran three minutes 43.73 seconds, the third fastest time in history.
The 22-year-old, who is also set to contest the 3,000m on day two of the Diamond League final, held off American Yared Nuguse (3:43.97) while Britain's George Mills was third in a personal best of 3:47.65.
Kipyegon continues thrilling year
At 13 Diamond League meets throughout the year, the world's best athletes have competed for points to qualify for the final at Hayward Field, which hosted the 2022 World Championships.
But the Olympic silver medallist was unable to follow that up in the final as world and Olympic champion Kipyegon blew away the field in the women's 1500m.
The Kenyan star, who broke three world records this summer, pulled clear on the penultimate lap and stretched her lead on the last to finish just outside her own 1500m record.
Kipyegon, 29, won in a time of 3:50.72 for her fourth Diamond League title, with Ethiopia's Diribe Welteji second (3:53.93) and Muir third in 3:55.16 - her second-fastest time, after the one she ran to win silver at Tokyo 2020.
In the men's 100m, 2019 world champion Coleman made a fine start to go clear of Lyles, and although the new world champion fought back, he had left it fractionally too late.
Coleman, who finished a disappointing fifth at last month's World Championships, held on to match the season's best time for the second time in two weeks, after also winning in 9.83 at the Xiamen Diamond League on 2 September. Lyles was second and Kenya's Ferdinand Omanyala third, both timed at 9.85.
Like Lyles, Richardson has established herself as a new star of US sprinting, claiming two world golds in Budapest last month.
But the 23-year-old never recovered after a flat start in the women's 100m, with 200m world champion Jackson, 29, edging clear to win in 10.70, with Ivory Coast's Marie-Josee Ta Lou second (10.75) and Jamaica's Elaine Thompson-Herah third (10.79).
British pair Dina Asher-Smith (10.96) and Imani Lansiquot (11.01) finished seventh and eighth.
There was disappointment for team-mate Matthew Hudson-Smith; the world silver medallist was in third position in the men's 400m when he pulled up on the back straight.
Grenada's former world and Olympic champion Kirani James, 31, held on to win in a season's best of 44.30secs, followed by American pair Quincy Hall (44.44) and Vernon Norwood (44.61).
Norway's Karsten Warholm suffered an upset in the men's 400m hurdles, the world and Olympic champion failing to win in two straight races for the first time since 2018.
He led going into the home straight, with Rai Benjamin third, but the American stormed past both him and Kyron McMaster of the British Virgin Islands to win in a world-leading time of 46.39secs, with Warholm second (46.53).