Warner, from London, Ont., gained 4,340 points from the first five events, including running 10.36 seconds to win the 100 metres. Kai Kazmirek of Germany is 96 points behind. American Gunnar Nixon is third, 101 points off the pace.
Theisen, from Humboldt, Sask., collected 3,816 points overall to lead Dafne Schippers of the Netherlands by five points.
Schippers was 160 points behind Theisen after the opening two events before beating the Canadian at the shot put and winning the 200.
Hanna Melnychenko of Ukraine is third with 3,740 points.