Johannesburg - Olympic semi-finalist Neil Versfeld fell short in his attempt to reach the men's 200m breaststroke final at the FINA World Championships in Shanghai, China on Thursday.
The 26-year-old South African was 16th in the semi-finals, finishing last in the second race in two minutes, 12.32 seconds (2:12.32).
In the morning session, Versfeld had qualified for Thurday's 200m breaststroke semi-finals.
He was 11th fastest of the qualifiers, finishing third in his heat in 2:12.54.
Fellow South African Darren Murray narrowly missed out on qualifying for the men's 200m backstroke semi-finals.
Murray, 20, was second in his heat in 1:58.73, finishing 0.25 seconds behind Omar Pinzon of Columbia who secured the last qualifying place.
Karin Prinsloo, 21, won her 100m freestyle heat in 55.57, but was 0.71 seconds slower than the last semi-final qualifier, finishing 26th fastest in the morning session.
South Africa dropped one place to 21st on the medals table, tied with Mexico, with three days of competition remaining.
Cameron van der Burgh had picked up two bronze medals, the nation's only medals, earlier in the week.