Lyles scorches to comeback win, Alfred conquers 100m
Lyles delivered a near-faultless run to clock 19.88 seconds to edge Olympic champion Letsile Tebogo into second with 19.97sec.
And Alfred timed a very comfortable looking 10.79sec to win the women's event-ending blue riband race ahead of American Jacious Sears (11.02).
But Lyles was the star of the show at a packed Stade Louis II in perfect balmy conditions. Tebogo had even said that when the American's face appears on meet posters, people want to come and see him perform.
And so it proved, Lyles coasting to a morale-boosting victory after successfully coming back from a tendon injury.
"I pray for times like this to be out here and do what I love. I come out here and I give my best," said Lyles.
The 10th competition on the 15-meet Diamond League circuit was loaded with a raft of top track and field stars, none less so in the electric men's 800m.
There was a late change in the wavelight technology that informs racers of record pacing in the two-lap race, with an unexpected tilt at Kenyan David Rudisha's world record from when he won gold at the 2012 London Olympics.
His compatriot and current Olympic champion Emmanuel Wanyonyi looked liked he might break the now mythical mark of 1:40.91, but he just faded at the line to win in a meet record and world lead of 1:41.44.
American Josh Hoey, the world indoor champion, was second in 1:42.01, with Algerian Djamel Sedjati rounding out the podium (1:42.20).
"I came to run a season's best and a meeting record," Wanyonyi said. "I came prepared. I gave my best today so I am happy with the result."
Bol on top form
There was another world-leading meet record in the women's 400m hurdles as world champion Femke Bol shot out a warning to the imperious Sydney McLaughlin-Levrone with a maiden victory in Monaco in 51.95sec.
The win took Bol's incredible streak of consecutive victories in the Diamond League since 2021 to 26, including four final wins.
The Dutchwoman easily saw off competition from Dalilah Muhammad and fellow American Anna Cockrell, Olympic silver medallist in Paris, who finished second and third.
"Running 51 is always very special, I don't do that every day," Bol said. "I am feeling good so far this season, I had a great start to it. I also did two 400m flats but I could see my shape getting better."
Armand 'Mondo' Duplantis again dominated the pole vault, the US-born Swede breaking the meet record with a successful vault of 6.05m on just his third effort of the competition, with only Greece's Emmanouil Karalis left to push him.
Once the two-time Olympic champion had cleared that height, he skipped 6.10m, forcing Karalis into a third failure, and second place.
Pundits might have reckoned that there would be no world record attempt, Duplantis happy to call it a day ahead of a month off competition with an eye on peaking at Tokyo in September.
But, ever the competitor, the bar was raised to 6.29m, 1cm higher than the record mark he set in Eugene last week. But it was not to be and three failures at the new height brought the Swede's evening to an end.
Dominican Marileidy Paulino edged American Aaliyah Butler by three-hundredths for victory in the 400m flat in 49.06sec.
The men and women's short hurdles were won by American Trey Cunningham (13.09sec) and Jamaica's Megan Tapper (12.34) respectively.
Ethiopia's Yomif Kejelcha won the men's 5,000m in 12:49.46 and Morocco's two-time Olympics champion Soufiane El Bakkali claimed victory in the 3,000m steeplechase in 8:03.18.