Caster Semenya capped a superb 2017 IAAF World Championships campaign for South Africa by capturing the team's third gold medal in London on Sunday night.
The two-time Olympic 800-metre medallist was a consummate winner of the two-lapper as she clocked a personal best and world-leading 1min 55.16sec.
American Ajee Wilson and Semenya's fellow Rio Olympic medallist Francine Niyonsaba tried their best to make the pace quick to blunt Semenya's final efforts.
The bell went in 57.98 but Semenya showed her usual patience and allowed the front runners their space before ominously gliding around the final bend and then putting her foot down to blast past in the final 50m.
Her victory margin was a hugely convincing 0.76sec over Niyonsaba as Wilson hung on for bronze in 1:56.65.
All nine finalists dipped under the 1:59 barrier in an impressive display of middle distance running.
Earlier Lebogang Shange had walked the race of his life to end fourth in the men's 20-kilometre walk on the final day of the championships.
Only in the last two kilometres did he drop back and he went on to walk a time of 1hr 19min 18sec for a national record. His previous best had been 1:20:06.
Victory went to Eider Arevalo who also set a national record, 1:18:53 and won Colombia's first gold of the championships.
Shange, who turned 27 just before the Championships, also had the satisfaction of beating Rio Olympics bronze medallist Dane Bird-Smith of Australia, the two having done many training kilometres in Australia over the last year or so.
Shange ended 14sec shy of winning bronze as Brazil's Cao Bonfim ran 1:19:04 in third place.
South Africa thus won six medals at these World Championships with Semenya winning two of them, bronze in the 1500m and then gold in the 800m.
She last won World Championships gold in Berlin, Germany back in 2009.
That put them into an incredible third spot on the medals table with Semenya's gold medal being joined by Wayde van Niekerk's 400m and Luvo Manyonga's gold. There was also 200m silver for Van Niekerk and two bronze medals for Semenya (1500m) and Ruswahl Samai in the long jump.