This was always expected to be a two way battle between the defending champion Veronica Campbell-Brown of Jamaica and World champion Allyson Felix of the USA and the semi-finals have confirmed this belief.
The pair looked supreme in winning their respective semi-finals and we are set for a treat in tomorrow night's final as Jamaica and the USA, the two superpowers of world sprinting, provide six of the eight finalists.
Defending champion Veronica Campbell-Brown kept alive her hopes of becoming the first women to successfully defend this title since Barbel Wockel of East Germany achieved the feat in 1980 with an eye-catching victory in the first semi-final.
Campbell-Brown made a blistering start and quickly made up the stagger on European Under-23 champion Yuliya Chermoshanskaya of Russia.
Campbell-Brown's compatriot Kerron Stewart also ran a hard first 100m and the pair entered the straight stride for stride with Muna Lee, of the USA, a metre further down.
It was Campbell-Brown, however, with her familiar wide arm action who opened up a clear lead on the opposition to stop the clock in 22.19. A stride behind were Stewart and Lee, who was given the same time of 22.29.
Critically, however, Stewart was awarded second in a photo finish which gives her the advantage of one of the middle four lanes in tomorrow night's final.
Running from lane nine, former World 200m champion Debbie Ferguson-McKenzie of the Bahamas snatched the fourth and final spot for the final in 22.51. Chermonshanskaya just missed out in fifth (22.57). Susanthika Jayasinghe of Sri Lanka, the 2000 Olympic 200m bronze medallist, finished seventh in 22.98.
Allyson Felix was a majestic winner of the second semi-final in 22.33. Jamaica's Sherone Simpson was quickest out of the blocks and she held a slight at halfway with Marshevet Hooker, in lane nine, also prominent.
But it was Felix, with her beautifully rhythmic stride who effortlessly pulled clear of the field over the final 80m to signal her intentions ahead of the final.
Hooker, the US Trials third placer, grabbed second in 22.50 shading a photo-finish verdict from Simpson after both recorded the same time.
Cydonie Mothersill, fourth in 22.61, made history to become the first athlete from the Cayman Islands to reach an Olympic track and field final.
Former European champion Muriel Hurtis-Houairi of France missed out in fifth in 22.71 with Bahrain's Asian Games champion Roqaya Al-Gassra sixth in 22.75.
Steve Landells for the IAAF