Mo Farah defended his 5,000m title while the Semenya stormed to victory in the 800m
It was a comfortable glide to gold for South Africa's Caster Semenya in the Women's 800m Final, while Mo Farah fought to defend every step of his lead on the back straight of the Men's 5,000m Final at the Rio Olympics.
25 year-old Semeyna, who has previously been subjected to gender tests to investigate if she should be competing in the women's event, set a national record in claiming her gold medal.
She finished in one minute 55.28 seconds with Francine Niyonsaba of Burundi trailing far behind in second place. Semenya was the silver medallist in 2012, behind Russia's Mariya Savinova who has since been named in a doping report and could be facing a lifetime ban.
Meanwhile, the path to first place, and double double glory, was less routine for Great Britain's Mo Farah. The final 200m required a full sprint to distinguish Farah from the rest of the chase, resulting in the reigning champion defending his title in 13 minutes 3.30 seconds.
This latest achievement added to Mo Farah's locker makes him just the second man to win the 5,000m and 10,000m titles.
The last athlete to do so was Finland's Lasse Viren, who completed the long-distance double at the Munich 1972 and Montreal 1976 Olympics.