Great Britain have had to rely on a fastest-loser's place in order to progress through to the men's 4 x 100m relay final.
The quartet of Richard Kilty, Harry Aikines-Aryeetey, James Ellington and CJ Ujah were drawn on the inside lane and despite three safe changeovers, they entered the final leg in fourth place.
Ujah finished strongly but after failing to move ahead of either Japan, Jamaica or Trinidad and Tobago, they were forced to settle for fourth place in 38.06s.
In the first semi-final, USA eased to victory in a season's best of 37.65s.
