Jenny Meadows leads a compact group in the heats of the women's 800 (© Getty Images)
Caster Semenya, Janeth Jepkosgei and Jenny Meadows the first three across the line in the Berlin final two years ago cantered into the semi-finals - as did Russia's 2011 world leader Mariya Savinova.
Meadows in the first heat ran a perfect race sitting on the shoulder of Kenya's Eunice Sum who went through the bell in 1:01.35 until getting clear 100m away from the line and finishing in 2:01.11.
Behind the USA's Maggie Vessey, Rosibel Garcia - the Colombian set a season's best of 2:01.33 - and Sum also made it by right to the semis where they all know the Race is going to be a lot quicker.
Great Britain's Meadow's summing up the task ahead, said: "There are more than eight great girls in the world this year, so I see the semi-final as a little bit more nerve racking than the final."
The second heat was all about who would finish second to Kenia Sinclair, now concentrating on the 800 after having spent part of the summer building up strength over the 1500m, who won in 2:01.66.
The Jamaican record holder led from gun to tape to hold off Halima Hachlaf, the eighth fastest in the world this year - but with five Russians topping the rankings the sixth quickest competing in Daegu.
Ukrainian Yuliya Krevsun fourth two years ago when trying to stay with Semenya the runaway winner, placed third squeezing between Ethiopia's Fantu Magisdo and Maryna Arzamasdava of Belarus with the latter also progressing automatically.
Janeth Jepkosgei the 2007 champion who surrendered her title two years ago to Semenya, really brought life and speed to the competition when dominating her race, easily the quickest of the day.
The 27-year-old Kenyan motored through the first lap in 58.46 - significantly Russia's Ekaterina Kostetskaya stayed a couple of metres off the pace - before continuing the momentum and winning in 1:59.36.
Kostetskaya a former World junior 400 Hurdles gold medallist, was a second in 1:59.61 with Alysia Johnson Montano of the USA 1/100sec behind and Briton Marilyn Okoro (1:59.74) also qualifying automatically.
The appearances of South African Semenya and Savinova - the latter's purple patch since Berlin where she placed fifth has seen her win the 2009 European Indoor, the following year's World Indoor and last summer the Euro outdoor gold medals -highlighted the next round.
It was the 26-year-old Russian who was given the heads up as in a tight finish - 0.03sec separated the first three with herself and Semenya sharing the same time of 2:01.001 ahead of Cherone Koech.
The USA's Alice Schmidt led through the bell in 59.99 with the defending champion moving onto her shoulder at the beginning of the backstraight. Down the home stretch she kicked again chased by Savinova and Kenya's Koech and was followed home by the American pacemaker.
Finally Annet Negesea after a 1:00.53 first lap from Svetlana Usovich of Belarus, edged herself into the lead halfway down the backstraight. The 19-year-old Ugandan despite strong challenges from her rivals maintained the curb to win in 2:02.75.
Behind and almost alongside, last year's 19-year-old World junior bronze medallist, was Algeria's Zahra Bouras, Lucia Klocova of Slovakia and Ukraine's Liliya Lobanova.
Lauren Lee and David Martin for the IAAF
