Great Britain's 4x400m men's relay team have been disqualified from the event despite winning their heat. The quartet of Nigel Levine, Delanno Williams, Matt Hudson-Smith and Martyn Rooney produced a storming performance to win in a time of 2:58.88.
In the immediate aftermath of the race, Rooney - who produced a stunning 43.8-second leg to take Britain to victory - revealed his pride at having bounced back from his underwhelming display in the individual 400m event. "I want to celebrate this. I am so proud how we preformed," he told the BBC.
"We had a tough draw, but the guys rose to the occasion. My last interview was terrible so I don't want to swear in this one. I think all our training is paying off."
However, his joy soon turned to frustration as Britain were disqualified for a barely-noticeable infringement from Rooney, who was deemed to have started his anchor leg in the wrong position. The decision prompted boos from the crowd and brought a bemused reaction from four-time Olympic champion Michael Johnson.
"It has to have been a judge that decided he saw something somewhere that they decided was an infringement, but I just can't think what that could be," Johnson admitted.
By contrast, Team GB's 4x400m women's quartet of Emily Diamond, Anyika Onuora, Kelly Massey and Christine Ohuruogu finished second in their relay heat with the fourth-fastest time overall to qualify for the final. Of their medal hopes, Ohuruogu said: "We have a strong medal chance but we are trying not to get too excited."