2018 IAAF World Indoor Championships – Men's 400 metres

For the first time ever in a World Championship, every runner in a single preliminary heat was disqualified. It was the third heat, where first returning silver medalist Abdalelah Haroun false started himself out of the heat. Then, in the process of winning the heat, #5 runner of all time[3] Bralon Taplin broke from his lane too early. The other three remaining runners, Austris Karpinskis, Alonzo Russell and Steven Gayle followed his lead and also broke too early.[4] 2012 Champion Nery Brenes also found himself disqualified after winning the fifth heat.[5] With two place qualifiers missing, it opened the door for Juander Santos and Mikhail Litvin to take the extra time qualification positions in the semi-final round.

In the final, Óscar Husillos was given the advantageous lane 6 starting position. With a fast start and aggressive first lap, Husillos was first to the break line and used it to deftly close the door and take the lead with a lap to go. Inside of him in lane 4, Pavel Maslák held the advantage over Luguelín Santos in lane 5 as they got squeezed by Husillos. Santos tried to force his way around Maslák, making Maslák hold out his harm to protect his position, but Santos took the second position in chase of Husillos. Behind them, Michael Cherry tried but was unable to get around Maslák. Three meters further back, Aldrich Bailey was also trying to catch Cherry but unable to make progress, with Deon Lendore chasing two metres back. As they reached the final straightaway, Santos made one final run at Husillos, who desperately leaned for the finish line in an impressive 44.92. Everyone held their position except Baily, who eased up on the final straightaway, passed by Lendore just before the line.

In an additional case of aggressive enforcement of the rulebook in this event, Husillos and Santos were disqualified for lane violations, giving Maslák his third consecutive championship,[6] Cherry the silver and Bailey letting Lendore pass at the end cost him a bronze medal that Lendore will receive. The disqualifications were booed by the crowd but were upheld by video evidence on appeal.[7] If it were allowed to stand, Husillos time would be the #6 performance of all time, and the European record.[8]