LONDON (AP) If it seemed as though there were miles between Wayde van Niekerk and his closest competition on Tuesday - well, that wasn't so far from the truth.
On a chilly evening in which the South African sprinter eased up before the finish line and still won his second straight 400-meter world title by .43 seconds, the man who was expected to give him the toughest test wasn't even allowed in the stadium.
The stomach virus that hit a number of athletes at the world championships earlier in the week morphed into a full-fledged mess a few hours before the 400 final, when video surfaced of Isaac Makwala of Botswana - who has pushed Van Niekerk in races all season - being escorted away from the athletes' entrance to the stadium.
Makwala insisted he felt fine. But he vomited Monday before the heats of his other race, the 200 meters, and the IAAF said doctors checked him, determined he had norovirus and, per the recommendation of health regulators in Britain, told him he had to stay off the premises for 48 hours.
''I came here for a medal,'' a healthy looking Makwala said in an interview with BBC Sports. ''Some people force you to withdraw. I'm OK to run, but someone's saying you can't run. It's a bad thing.''
The IAAF put out its own statement defending the decision, saying it ''is very sorry that the hard work and talent of Isaac Makwala won't be on display tonight but we have to think of the welfare of all athletes.''
But that was hardly the end of the debate.
Social media erupted with second-guessing and hypotheticals, including: What would the IAAF have done if this had been Usain Bolt? And, What's the use of telling someone you're sick when they're just going to bar you from the stadium?
The innocent bystander was Van Niekerk, who, truth be told, would've been favored to win this race had Makwala been there anyway. He is the world-record holder and Olympic champion and is being touted as the planet's greatest sprinter in a post-Bolt world.
Van Niekerk won the race in a pedestrian-for-him 43.98 seconds, which was still two full paces ahead of silver and bronze medalists Steven Gardiner and Abdalelah Haroun.
''It was just definitely a heartbreaking moment,'' Van Niekerk said. ''I saw him just before the 200-meter heat and the only thing I could think of was wrapping my arms around him and telling him to get well soon. As much as you want to leave with gold medals, you want to go out there with the best guys also out there.''
Makwala wasn't the only top runner missing.
Minutes before her heat in the 200 meters was to start, Tori Bowie withdrew. The American was in the stadium and went through warm-ups, but the scrapes and bruises on her hip from the dive over the line in her 100-meter victory two nights before hadn't healed enough for her to race again. Her status for the relays Friday and Saturday was to be determined.
Also missing was David Rudisha of Kenya, the world-record holder at 800 meters who pulled out last week with a leg injury - a move that turned the event into a free-for-all. Pierre-Ambroise Bosse of France wound up with the gold.
Other winners were no surprise: Conseslus Kipruto of Kenya in the steeplechase and Barbora Spotakova of the Czech Republic in the javelin - a victory that came a decade after her last world title.
America's brightest moment came from Sam Kendricks, who was the only pole vaulter to clear 5.95 meters and captured his country's third gold medal of the meet.
Third-place finisher Renaud Lavillenie of France - booed mercilessly at last year's Olympics when he set the bar at a height that would've won him gold over a Brazilian favorite - also used his final attempt this year to go for the win at 6.01 instead of trying for second at 5.95.
''Silver or bronze, it's almost the same,'' Lavillenie explained. ''You have one champion and two other medalists.''
Pole vault may have been the best pure competition, but the evening will also be remembered for the showdown that never transpired: Makwala vs. Van Niekerk.
''As an athlete, as a brother, I would've liked to see my brother given a chance and do whatever he could do best,'' said Nijel Amos, an 800-meter finalist from Botswana.
Hard to argue with that - and Van Niekerk certainly did not.
''I have sympathy for him,'' he said. ''I wish I could give him my medal.''
He might have one to spare. With Bolt not racing in the 200, and Makwala - who would've contended at that distance, too - unable to get to the starting line, the odds of Van Niekerk completing the 200-400 double just keep getting better.
More AP track coverage: https://www.apnews.com/tag/London2017