The United States topped the medals table at the IAAF World Championships with 10 golds, but the mega biennial event fittingly climaxed with yet another upset result in the men's 4x400m with Trinidad and Tobago claiming the title.
The Americans also took 11 silver and nine bronze for a total of 31 medals. Kenya were second with five gold, two silver and four bronze. They were followed by South Africa with three gold, one silver and two bronze.
The United States were looking to defend their crown in the men's 4x400m and close out the programme on Sunday night with their seventh successive title in this event.
However, it became clear that they were missing the injured LaShawn Merritt—who anchored their quartet to a narrow win over Trinidad and Tobago at the last World Championships in 2015.
In a reversal of the outcome in 2015, Lalonde Gordon overhauled world finalist Fred Kerley of the US on the anchor leg to gift Trinidad and Tobago the gold with a time of two minutes and 58.12 seconds. The Americans had to be content with silver at 2:58.61.
The women's 4x400m final played out exactly as expected with Phyllis Francis anchors the USA to gold 3:19.02 ahead of Britain (3:25.00) and Poland (3:25.41).
This was the United States' 10th gold medal of the championships and the 11th of their star runner Allyson Felix's career. After running the second leg of their gold medal-winning 4x100m team on Saturday evening, Felix had become the most bemedalled athlete in World Championships history with 16 medals. After claiming her second title of the championships in the 4x400m, Felix has matched Jamaican legend Usain Bolt's haul of 11 gold medals.
But while Bolt bowed out of competition at this championships, it is full steam ahead to the 2020 Olympics in Tokyo for Felix.
In the men's 50km racewalk, 39-year-old Yohann Diniz of France became the oldest man to win a gold medal in World Championships history.
The world record-holder required an unscheduled early race pit stop but he quickly slotted himself back into the leading pack, although not for too long. By the 10km checkpoint, Diniz was already 40 seconds clear of the pursuers and his lead had doubled over the course of the next 10km segment.
Diniz only resumed full training as recently as June after sustaining broken ribs in a car accident but he still crossed the finish line in a championship record of 3:33:12, a time second only to his world record of 3:32:33.
The first edition of the women's 50km race walk at the World Championships was capped with a world record from Ines Henriques of Portugal.
Henriques, who clocked 4:08:26 earlier this season, ended up finishing two minutes inside that time, crossing the finish line in 4:05:56 ahead of China's Yin Hang who created a new Asian record of 4:08:58.
Ines Henriques in the 50km race walk at the IAAF World Championships London 2017 (Getty Images)
In contrast to the 50km, both 20km races went down to the wire. China looked on course for another brace of medals in the women's race with Yang Jiayu winning in 1:26:18 by one second ahead of Mexico's Maria Guadalupe Gonzalez but disaster struck for Liu Xiuzhi, disqualified on the purple carpet leading into the finish. Italy's Antonella Palmisano was the beneficiary, taking bronze in 1:26:36.
The men's 20km race walk was another see-saw affair which saw the medal positions change constantly in the last five kilometres. Eider Arevalo of Colombia won gold in a national record of 1:18:53 ahead of the teenaged Sergei Shirobokov of Russia (1:18:55) and Brazil's Caio Bonfim (1:19:04).
Kenya continued their domination of the men's 1,500 metres event with Elijah Motonei Manangoi and Timothy Cheruiyot taking the top two spots on the podium.
Manangoi won the gold medal with a time of 3 minutes and 33.61 seconds on Sunday night. Cheruiyot, who gave his compatriot a tough fight during the sprint on the final stretch, narrowly missed out on the top spot and had to be content with the silver.
Cheruiyot was just 0.38 second behind the winner, finishing with a time of 3:33.99. Filip Ingebrigtsen of Norway finished in 3:34.53 to take home the bronze medal.
It was the third time in the past four World Championships that Kenyan athletes had filled the top two spots in the men's 1500m.
Another Kenyan, three-time reigning champion Asbel Kiprop, finished a disappointing ninth in 3:37.24.
South African star Caster Semenya produced a strong finish to regain the mantle of world champion in the women's 800 metre event at the London Stadium here.
The reigning Olympic champion produced a time of one minute and 55.16 seconds—the fastest in the world this year—to win gold at the IAAF World Championships on Sunday night.
This was the second World Championships gold in the 800m event for the 26-year-old. Her first World Championships title came at the 2009 edition in Berlin, a year after she won gold at the World Junior Championships.
Rio Olympics silver medallist Francine Niyonsaba of Burundi came in second with a time of 1:55.92 while American athlete Ajee Wilson finished third in 1:56.65.
Semenya has won every 800m race since finishing eighth at the ISTAF Meeting in Berlin in September 2015.
Meanwhile, Croatia's Sandra Perkovic now has two world discus titles to go alongside her pair of Olympic titles, as well as her four European crowns.
Perkovic's second-round throw of 70.31m—the first 70-metre-plus throw in a World Championships since 1991—placed her in an unassailable position. Dani Stevens from Australia added nearly two metres to her career best and creted Oceanian record with 69.64m to take silver. Melina Robert-Michon of France took the bronze at 66.21m.
In the men's high jump, Mutaz Essa Barshim of Qatar won gold with an attempt of 2.35m while 20-year-old neutral athlete Danyll Lysenko did well to take silver with 2.32 in his first global championship at the senior level.
Majd Eddin Ghazal of Syria registered 2.29m to take the bronze. Mexico's Edgar Rivera and Mateusz Przybylko of Germany finished fourth and fifth, respectively.
Rivera and Przybylko hd also registered best attempts of 2.29m. But the Syrian took the bronze on countback by virtue of a second clearance at 2.29m. He thus became his country's second medallist in World Championships history after Ghada Shouaa, who won a gold medal in the heptathlon in 1995 and bronze in 1999.
Lysenko was the only athlete who was able to give a strong challenge to the eventual champion at the London Stadium on Sunday night.
The 2013 Youth Olympic champion topped 2.20m and 2.25m with his first couple of attempts. He then cleared 2.29m and 2.32m in his subsequent attempts to take control of the silver medal position.
The next height, 2.35m—one centimetre better than his career best—proved too high but by then he had done enough to guarantee the second spot.
