BEIJING (AFP) - Veronica Campbell-Brown won her second Olympic 200-meter final in a row on Friday, continuing Jamaican domination over US runners as champion Allyson Felix finished second as she did in 2004. Campbell-Brown won in a personal-best time of 21.74 seconds, matching the eighth-best all-time performer with the fastest time in the world this year, with American Felix second in 21.93 and Jamaican Kerron Stewart third at 22.00. A US-Jamaican women's grudge match began when Jamaicans swept the women's 100m medals with three Americans adrift and Jamaican Usain Bolt's world record triumphs in the men's 100 and 200 added to the misery for US sprinters. American Muna Lee was fourth in 22.01 with compatriot Marshevet Hooker fifth in 22.34. Both times were personal bests. Jamaica's Sherone Simpson came sixth on 22.36. Campbell-Brown jumped out fast and by the turn was ahead. She powered into the straight and opened a gap with Felix, who held off Stewart's late charge at the line. Stewart claimed her second medal of the Games after a 100m bronze. Reigning Olympic and two-time world champion Jeremy Wariner will face top rival LaShawn Merritt in an Olympic 400-meter final showdown of US stars later Thursday.Merritt, the 2007 world runner-up to Wariner, beat his arch-rival in the US Olympic trials but lost twice to him last month in Europe, setting the stage for their most meaningful meeting yet. US men have dominated the Olympic men's 400, winning the past six gold medals in the event and 11 of the past 13. Other later gold medals on offer include the women's javelin, men's triple jump and men's 110m hurdles, where Cuban world record holder Dayron Robles will be challenged by Americans David Oliver and David Payne. Reigning world champion Maryam Yusuf Jamal of Bahrain won her qualifying heat in the women's 1,500m to take her place in the field of 12 for Saturday's final.Russian former two-time world champion Tatyana Tomashova and compatriot Yelena Soboleva, the two top 1,500 performers in the world this year, were not allowed to compete at Beijing after testing positive in pre-Games drug tests. World champion Olga Kaniskina of Russia led from gun to tape to win the women's 20km walk in an Olympic record of 1hr 26.31min.