Usain Bolt
Bridgette Hartley qualified first in her semifinal canoe sprint, in the K1 500m single women heats in Eton Dorney.
She came second in her heat, 1:53.051, and went on to win her semifinal in an improved 1:51.286, taking her through to Thursday morning's final.
In the men's 110m hurdles, Lehann Fourie came second in his heat, in 13.49 seconds, which was a season's best for him.
He finished behind Cuba's Orlando Ortega (13.26) and will compete later Tuesday in the third of the semifinals.
Bronze medallist at the World Championships in 2011, Sunette Viljoen qualified in third place for the javelin finals, with a throw of 65.92m
In Wednesday night's final, she will be up against Czech Barbora Spotakova, the gold medallist at the 2008 Olympic Games and Germany's Christina Obergfoll, who took bronze in Beijing.
Anaso Jobodwana came second in the men's 200m heats, in 20.46 seconds, behind Christophe Lemaitre of France, who qualified in 20.34.
Usain Bolt, running in the first heat, qualified in 20.39 and the two could meet in the semifinals on Wednesday evening.
Jobodwana, studying at Jackson State University, Mississippi, received a special message of good luck from his father's boss, Correctional Services Minister Sibusiso Ndebele, who wished him well for the Olympic Games. – Sapa