World champion in the new European record time of 44.33 s was the 1986 vice European champion Thomas Schönlebe from the GDR , who also won the 1983 World Cup bronze with his country's 4 x 400 meter relay . The two best of the year in the world and actual favorites of this competition took second and third place. Second was the Nigerian Innocent Egbunike , who had set a new world championship record with 44.26 seconds in the semifinals. Bronze went to the US world best of the year Harry Reynolds , who three days later won the gold medal with the US relay over 4 × 400 meters.
The preliminary round was carried out in six runs. The first four athletes per run - highlighted in light blue - as well as the eight fastest runners - highlighted in light green - qualified for the quarter-finals.
From the four quarter-finals, the first three athletes - highlighted in light blue - as well as the four fastest runners qualified for the semi-finals. However, there were two athletes of the same kind who were four ranks behind the athletes who were qualified by their placement. Both were admitted to the next round. So five runners reached the semi-finals over their time - highlighted in light green. A total of seventeen runners qualified for the semi-finals, which was not a problem because the stadium had the nine lanes required in one of the two semi-finals.
In the final, Derek Redmond could not quite build on his strong performance from the semifinals, with which he would have won silver, and finished fifth
The 1984 Olympic runner-up, Gabriel Tiacoh, came seventh here
Results in the IAAF Statistics Handbook for the 2019 World Cup in Doha, Men 400 m, Rome 1987 (PDF 10.3 MB, p. 104f), English, accessed on March 21, 2020