GB cruise into mixed 4x400m relay finalpublished at 07:25 British Summer Time 3 August
Athletics - mixed 4x400m relay
Great Britain will compete for a mixed 4x400m relay medal on Saturday after the quartet of Samuel Reardon, Laviai Nielsen, Alex Haydock-Wilson and Nicole Yeargin set a national record to win their heat in 3:10.61.
The United States qualified fastest for that final in a new world record of 3:07.41.
The final takes place tonight at 19:55 BST.