Johannesburg - South Africa Caster Semenya looked every bit the medallist when qualifying through her 800m semi-final at the 12th World Athletics championships in Berlin on Monday night.

The 18 year old adopted similar tactics to the first round sitting in behind first lap leader Tetliana Petlyuk, the 2008 world Indoor Champion.

As the bell rang in 58.11 seconds, Semenya moved to the front, responding to all attempts to chase. The Polokwane based athlete crossed the line in one minute 58.66, silencing any doubts that her 1:56.72 at the African Junior Championship was a fluke.

When I woke this morning I knew my leg was fine. I knew I could run to win, said Semenya who will determine her final tactics with her coach Michael Seme.

Defending World Champion, Janeth Jepkosgei, who fell in Semenya's first round heat and was reinstated for the semi's, held on for third behind the fast finishing Jennifer Meadows from Britain in 1:59.47.

Even her strongest opposition is wary of the new kid on the block. A fast race suits me but anything can happen in the final. I think the South African could give me problems, said the Kenyan.

Semenya became only the fourth South African to break the two minute barrier, and in doing so took over two seconds from Zelda Pretorius's 1991 record.

The semi-final journey was not comfortable for Peter van der Westhuizen whose fast start put him out in front of the first of three semi-finals. Forced into front running the Kempton Park man took the field through to the bell Frenchman Mehdi Baala took to the front with American's Bernard Lagat and Lopez Lomong wasting no time in following the lead.

By the final bend van der Westhuizen had been swallowed up and spat out the rear of the field facing a hopeless task. Morrocan Amin Laalou pulled the five qualifiers through in 3:36.68.

"I don't know what I could have done differently. Its not where I wanted to be (at the front). I had a better chance of a fast race even though I sacrificed myself doing it", said van der Westhuizen, who has little reason to be disappointed in his first major championship.

South African attention moves forward to the 3000m steeplechase where Ruben Ramolefi faces a 15-strong field.

The Kenyans have dominated this event with defending world champion Brimin Kipruto, 2004 Olympic Champion and current world leader Ezekiel Kemboi and Paul Koech, who has cracked eight minutes six times, providing an awesome trio to tackle. Add in Frenchman Bouabdella Tahri and fifth ranked Tareq Mubrak and the South African has a mountain to climb.

In the morning session Thuso Mpuang is in the ninth and final heat of the 200m, which marks the commencement of part two of the Usain Bolt show. Pieter Smith faces up to Helsinki and Osaka champion Jeremy Wariner in the sixth heat of the 400m.