Olympic champions U.S. lead the way in women's 4x100m relay heats

The Olympic champions, featuring Aaliyah Brown, Allyson Felix, Morolake Akinosun and Ariana Washington, won the opening heat in a time of 41.84 seconds, challenged only by the British quartet who came second in 41.93.

The third automatic qualifiers were Switzerland, who ran a national record time of 42.50, pointing to a high calibre final later on Saturday.

Jamaica, the defending champions, were missing seven-times world championship gold medallist Shelly-Ann Fraser-Pryce, but still qualified second fastest in the final heat ahead of Brazil. Germany won the second heat in 42.34.

Completing the final lineup were the Netherlands, featuring twice 200m champion Dafne Schippers, and 2015 bronze medallists Trinidad and Tobago. (Reporting by Christian Radnedge; Editing by Toby Davis)