James will meet Kristina Vogel in the last four in a rerun of the Track Cycling World Championships final after the German's 2-0 quarter-final defeat of Jess Varnish.
Welshwoman James qualified sixth fastest and met Elis Ligtlee in the last eight, defeating the Dutchwoman by half a wheel in the first contest before a more comfortable victory in the second bout.
Vogel, beaten by James to the world title in Minsk in February, was a comfortable winner in each contest with Varnish, who was riding in her only event of the weekend.
The 22-year-old from Bromsgrove will now race for fifth to eighth place.
Olympic champion Anna Meares of Australia beat Virginie Cueff of France 2-0 to set-up a semi-final with Hong Kong's Lee Wai Sze, who edged Stephanie Morton of Australia 2-0 in her last-eight bout.
Meares missed Minsk and was racing in her first global competition since London 2012.
She had an enduring rivalry with Victoria Pendleton, who has now retired, and in Delhi in October 2010 was pushed close to Commonwealth Games gold by an 18-year-old James.