ON FIRE: SA star Caster Semenya

Olympic gold medal hopefuls Caster Semenya and Wayde van Niekerk continued their world-beating form in Monaco this weekend.

Semenya eclipsed her own South African 800m record on Friday in an IAAF Diamond League meet and can now take aim at the world record and a gold medal at Rio next month.

The 25-year-old Semenya, the 2009 world champion, announced herself emphatically as the absolute favourite in Brazil when she charged down the home straight to win in 1:55.33, beating her previous mark of 1:55.45, which she achieved in Berlin when winning world championship gold.

Semenya outclassed her biggest rival, Francine Niyonsaba, by nearly a second as the Burundian finished in 1:56.24 - a personal best and a new national record.

Van Niekerk claimed a sparkling victory in the men’s 400m. The Kraaifontein-born sprinter clocked 44.12 seconds, finishing ahead of rivals Machel Cedenio (Trinidad and Tobago) and Bralon Taplin (Grenada).

The other standout South African athlete on the night was sprinter Carina Horn.

The national record-holder clocked a quick 11.14, not far off her SA mark of 11.06, which was particularly good considering she was in lane eight on what is a tight track at the Stade Louis II stadium.

Long jump star Rushwahl Samaai finished fourth in his event with an effort of 7.93m, Javelin juffrou Sunette Viljoen will look to improve on her fifth place with was five metres off the gold mark and 110m hurdles African champion finished seventh in a tight race.