George finished third in her semifinal heat, crossing the line in 12.65 seconds. Zelinka was second in her heat in 12.66.
The taller George had a long, controlled stride all the way through her race. Zelinka fell behind quickly, but used her speed to power past most of the field, leaning across the line just ahead of American Lolo Jones (12.71), who qualified seventh.
This is Zelinka’s second event of the London Games. She finished sixth in the women’s heptathlon over the weekend.
Australia’s Sally Pearson, the reigning world champion and 2008 Olympic silver medallist, had the fastest time in the heats, clocking in 12.39.
Defending Olympic champion Dawn Harper of the United States was .07 behind Pearson.
The rest of the final consists of American Kellie Wells (12:51), Nevin Yanit (12.58), of Turkey, and Austria’s Beate Schrott (12.83).
Nikkita Holder, of Pickering, Ont., failed to qualify for the final after registering a distant time of 12.93.