The 2019 World Athletics Championships in Doha were the "best we have ever had" in terms of athletic performance, says IAAF chief Lord Coe.
And Coe once again defended the hosting of the event in Qatar as the 10-day competition drew to a close.
There has been criticism of the poor attendances and scheduling, while issues of alleged human rights abuses in Qatar were raised.
"Our sport is in pretty good shape," said the Briton.
"It is pretty clear to us on athlete performance this is the best World Championships we have ever had."
USA sprinter Allyson Felix broke Usain Bolt's record for the most World Championship gold medals, winning her 12th in the 4x400m mixed relay and her 13th in the women's event - 11 months after giving birth.
Other highlights included Felix's fellow American Dalilah Muhammad improving her own world record in the 400m hurdles, while Dina Asher-Smith became the first British athlete to win three medals at a major global championships.
Elsewhere, the USA's Noah Lyles outlined his potential as Bolt's heir apparent with 200m gold and Mutaz Essa Barshim thrilled the home crowd by retaining his high jump title.
"It is really important the sport moves around the world, and it cannot forge its relationships based on political structures or transitory political systems," added Coe.
"We would not have sporting relationships [otherwise]. That is why sport will continue to work and sweat as hard as it does to make social change.
"We are not competitors, we are collaborators and organisations that are smart are actually partnering as they realise they can elicit that change."
Speaking on the championships' final day, former 1500m Olympic champion Coe added: "It's important sport can rise above political structures.
"Fundamentally, I believe sport is the best diplomat we have."
'The first two days were difficult'
Poor attendances were one of the major talking points with only the second Friday having crowds of more than 40,000 inside the Khalifa Stadium, which holds 48,000.
Last Sunday - the day of the women's 100m final, when Asher-Smith won silver - only 7,266 were present. The average attendance during the first eight days was 20,000.
It was also announced that tickets had been bought by the organising committee, partners and public institutions and distributed to "embassies, employees, schools and higher education".
Doha 2019 organising chief Dahlan Al Hamad said: "Filling the stadium is the challenge for all sports.
"The first two days were hectic and difficult. I hope you saw in the past few days the stadium fill up because people had started to see results of athletes.
"We are really thrilled we received these championships and expanded the horizon of athletics in the Middle East region."
'I haven't read Salazar report'
A shadow was also cast over the championships when Alberto Salazar - Mo Farah's former coach - was banned from the sport for four years after being found guilty of doping violations.
Many athletes who are members of Salazar's Nike Oregon Project faced questions on their relationship with the Cuban-born American, including Sifan Hassan who won an unprecedented 1500m-10,000m double - the former in a championship record.
"This was a very hard week for me and I was just so angry," said the Dutchwoman. "I've been clean all my life. I work hard."
Coe said the Athletics Integrity Unit (AIU) would conduct a review of Salazar's case after calls to investigate athletes linked to the coach.
"We have an Athletics Integrity Unit that clearly will take a big interest in the findings of Usada [United States Anti-Doping Agency]," he said.
"I'm entirely confident that the AIU will want to look at the whole case and will want to think about the implications of that."
However, the IAAF chief admitted he had not read the Usada report.
"I've read the executive summary," he said. "That and the announcement of the suspension was enough for me to get into business mode."
'Hosting championships in Doha a mistake' - analysis
Four-time Olympic champion and BBC athletics pundit Michael Johnson
The decision to bring the championships [to Doha], there were far more more negatives than positives. I think it was a mistake and I think the athletes would say the same thing.
The other thing we learned is that doping continues to be a problem in the sport and fans have zero tolerance for it. But I remind them that this sport leads in catching people and punishing people. That we should be proud of.
The athletes are always amazing. This sport is amazing. It's no surprise the athletes put on fantastic performances. Kudos to them.