Great Britain have secured four out of a possible five relay slots for the Olympics in Paris this summer via the World Athletics Relays event in the Bahamas.
The women’s 4x100m team won their heat on the first day, while the 4x100m men’s quartet, plus the 4x400m men’s and women’s teams, were all second in their heats.
The top two teams in each heat progressed to the final on day two while also securing Olympic places.
The second day’s racing will decide lane seeding positions for the Games.
The women’s 4x100m team of Asha Philip, Imani-Lara Lansiquot, Bianca Williams and Amy Hunt recorded a season’s best time of 42.33 seconds as they won the fourth heat.
They finished second fastest overall on day one behind the United States, who had won the first heat.
“That was incredible, it was my first time with these three girls,” said Hunt.
“They’ve been so absolutely amazing in trusting me and mentoring me and making sure I am on it.
“So, to get that baton and cross the line with the biggest smile on my face that was one of the most fun races I have ever done.
“We got here, we did our job, we executed so we’re super, super, happy.”
The men’s team of Zharnel Hughes, Nethaneel Mitchell-Blake, Richard Kilty and Eugene Amo-Dadzie were second behind France in their heat with a season’s best of 38.36s.
Victoria Ohuruogu, Hannah Kelly, Nicole Yeargin and Lina Nielsen ran the women’s 4x400m in three minutes 24.89 seconds and were beaten by Ireland.
The men’s 4x400m team of Matthew Hudson-Smith, Toby Harries, Lee Thompson and Lewis Davey, who ran 3:02.10, finished behind Italy in their heat.
The mixed team of Brodie Young, Ama Pipi, Charles Dobson and Laviai Nielsen were third in their heat, behind winners Ireland and Belgium.
They still have a chance to book a quota place in Paris if they can finish in the top two of their heat on day two.
One of the highlights of day one was Italy, including Olympic 100m champion Marcell Jacobs, being drawn in the same men’s 4x100m heat as the United States, featuring world 100m winner Noah Lyles.
Jacobs ran the second leg for his team, while Lyles anchored the American quartet as the US won the race in a world leading time of 37.49, with Italy second in 38.14.
