Elaine Thompson-Herah ran a stunning anchor leg to hand Jamaica victory in the women's 4x100m event at the World Relays on Sunday, while Letsile Tebogo helped host nation Botswana win the second fastest 4x400m in history.
Thompson-Herah, 33, took the baton from third-leg runner Lavanya Williams and headed into the final straight a couple of metres down on Canada's Donna Ntambue.
But the second-fastest woman ever in the 100m, a five-time Olympic champion, turned on the power and reeled in the Canadian.
The Jamaican foursome, also comprising Briana Williams and Jodean Williams, won in 42.00sec, with Canada second in 42.17 and Spain (42.31) rounding out the podium.
There was a dream finish to two days of high-octane action in the Botswanan capital as the country's men's team won the 4x400m relay.
Lee Bhekempilo Eppie led the Botswanans out in front of a raucous crowd, before reigning Olympic 200m champion Letsile Tebogo took over.
But the country's first-ever Olympic champion pulled up badly at the end of his lap, handing South Africa's Lythe Pillay the advantage.
It left world 400m bronze medallist Bayapo Ndori a mountain to climb on the third leg. He tracked down South African Leendert Koekemoer but could not break free.
It was neck-and-neck between Botswana, South Africa and Australia at the final baton handover.
But Botswana's world 400m champion Collen Kebinatshipibroke free from South Africa's Zakithi Nene 40 metres from the line to win in a blistering 2min 54.47sec, just 18 hundredths of a second slower than the world record set by a US quartet featuring Michael Johnson in 1993.
Competition was fierce with places at next year's world championships in Beijing were up for grabs, as well as qualification for the inaugural World Athletics Ultimate Championship in Budapest in September.
BIG US NAMES ABSENT
The men's 4x100m saw American anchor leg Pjai Austin hold off a fast-finishing Akani Simbine of South Africa for the win in 37.43sec.
With better-known US runners including Noah Lyles absent, Ronnie Baker, Max Thomas and Lance Lang completed the US team,
Jamaica set a new world record in the mixed 4x100m, a relatively new addition to the schedule at major championships.
Ackeem Blake, Tina Clayton, Kadrian Goldson and Tina's twin sister Tia Clayton raced to victory in a dominant 39.62sec.
The Jamaican quartet had become the first team to dip under 40 seconds when clocking an initial world best of 39.99sec in Saturday's heat.
"It's a great feeling, this event is somewhat new to us, this is my third time running it and all I can say is it was fun running with the guys," said Tia Clayton.
"To come out here and execute in the way I did and to do my ultimate best, I'm very grateful. And I finished the race injury-free, so yes, I'm very grateful."
There was a national record for the Jamaicans in the 4x400m mixed relay, but it was only good enough for second place behind the US winners.
Bryce Deadmon, Paris Peoples, Jenoah McKiver and Bailey Lear clocked 3:07.47 for victory, with the Jamaicans finishing 0.37sec off their pace.
Henriette Jaeger delivered a top-class final lap to hand Norway's women victory in the 4x400m relay in 3:20.96.
Jaeger outsprinted Blanca Hervas, who guaranteed Spain second spot ahead of Canada.