Lyles, the Diamond League winner, took the victory in 19.83 seconds, 0.12 faster than de Grasse. The Canadian adds a silver to his three career bronze medals in the world championships. He also has one Olympic silver and two bronzes.
Third place went to Alex Quinonez of Ecuador after Britain's Adam Gemili faded badly on the final stretch, finishing fourth. Defending world champion Ramil Guliyev of Turkey was fifth. It was the third gold medal of the night for the U.S. after wins for Sam Kendricks in the pole vault and Donavan Brazier in the 800.
Sam Kendricks of the United States has defended his pole vault title, beating Armand Duplantis after both cleared the best height at a world championships since 2001.
Kendricks and Duplantis both cleared 5.97 meters and failed their attempts at 6.02.
Kendricks took the title because he had fewer failures at lower heights, four compared to five for Duplantis, who represents Sweden but was raised in Louisiana.
Olympic champion Thiago Braz of Brazil settled for fifth on 5.70, and world record holder Renaud Lavillenie of France missed the final altogether after being eliminated in qualifying.
Kelsey-Lee Barber became the first Australian to win a world javelin title, overtaking two Chinese athletes with a 66.56-meter final throw. Liu Shiying was second and Lyu Huihui third. Barber dropped to the ground in shock when her result was shown on the big screen.
Less than 24 hours after distance running coach Alberto Salazar was banned for doping offenses, an athlete he trained won gold in the 800 meters.
Donavan Brazier took command of the field at the halfway point and took a comfortable win in 1 minute 42.34 seconds, ahead of Amel Tuka of Bosnia and Herzegovina.
Kenya's Ferguson turned up the heat on the final stretch to take bronze.
Salazar was banned four years for violations including possessing and trafficking testosterone, in a case related to his Nike Oregon Project stable of athletes. Brazier has not been accused of any wrongdoing. Salazar's credentials for the world championships have been revoked.
Olympic champion Shaunae Miller-Uibo has cruised into the final of the women's 400 meters, qualifying fastest despite visibly easing off on the final stretch.
The Bahamian won her semifinal in 49.66 seconds, well ahead of Wadeline Jonathas of the United States. The Nigeria-born Bahraini runner Salwa Eid Naser won another semifinal in 49.79, while Jamaica's Stephenie Ann McPherson took the third in 50.70.
Miller-Uibo is chasing her first gold medal at a world championships after 400 silver in 2015 and 200 bronze in 2017. The final is Thursday.
Compete in the world championship marathon, sit out the next three months. That's the message from Ethiopian track and field officials concerned about the heat in Qatar.
The federation says it "has decided that all Ethiopian athletes who took part in the Doha marathon should not take part in any other race before three months."
It says the decision is prompted by concern for the athletes' health and any who break the rules face "severe consequences."
Of the 68 athletes who started the women's marathon Friday in hot and humid conditions, 28 failed to finish — including all three Ethiopians taking part.
Ethiopian distance-running great Haile Gebrselassie told The Associated Press that athletes "could have died" in the conditions. The men's marathon is Saturday.
The 2012 Olympic champion Kirani James set the pace in the heats of the men's 400 meters, winning his race in 44.94 seconds.
Michael Norman of the U.S. and Emmanuel Kipkurui Korir of Kenya also set fast times to win their heats, but European champion Matthew Hudson-Smith of Britain's bid for a medal was ended by injury.
Hudson-Smith pulled up abruptly just after the start and collapsed with an apparent thigh injury. He was given medical attention and left the track in a wheelchair.
The reigning Olympic and world champion, South Africa's Wayde van Niekerk, is not competing because he hasn't fully recovered from a knee injury he suffered playing a charity tag rugby game in late 2017.
Once again, doping is overshadowing the action at the track and field world championships.
Less than 24 hours after renowned distance-running coach Alberto Salazar was banned four years for violations including possessing and trafficking testosterone, two athletes from his team will race in the men's 800-meter final.
Donavan Brazier and Clayton Murphy of the U.S., who have not themselves been accused of any wrongdoing, are among the medal contenders along with Ferguson Rotich of Kenya.
Salazar's credentials for the championships have been revoked and officials are formally notifying his athletes that they are forbidden from working with him.
Also Tuesday, Noah Lyles of the U.S. will battle Canada's Andre de Grasse in the 200 final, while medals are also up for grabs in the men's pole vault and women's javelin.
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