Johannesburg - South African athletes struggled at the fourth leg of the Diamond League series in Rome on Thursday night, with sprinter Simon Magakwe producing the strongest challenge of his compatriots.
Magakwe, turning out for the second time in the top-flight international season, delivered a more competitive performance than he did in Eugene at the weekend, despite clocking a slower time of 10.20 seconds.
While he had crossed the line in 10.13 in his previous Diamond League outing, he had finished last in that race.
The multiple SA champion was sixth in the Italian capital, 0.29 seconds behind American world leader Justin Gatlin who won in 9.91, after another strong surge in the second half.
Johan Cronje, who admitted before the event he was battling fatigue, settled for eighth place in the men's 1 500m race in 3:34.90, just five days after he broke Johan Fourie's 27-year-old national record in the mile (1.609km).
The South African was unable to close the gap after seven men broke clear on the final lap, with Kenyan Silas Kiplagat grabbing the win in 3:30.44.
Fellow middle-distance runner Caster Semenya had hoped to impress the Commonwealth Games selectors but fell well short of the 2:00.91 performance she needed to be considered before entries for the quadrennial showpiece close on June 12.
Semenya was sluggish from the start, hanging on at the back of the field as the leaders drew gradually clear up front.
She trailed home in 10th place in 2:02.66, and while it was a season's best in only her second race of the year, she was more than seven seconds off her five-year-old national record.
Kenyan world champion Eunice Sum secured victory in 1:59.49.
Discus thrower Victor Hogan also finished 10th in his event with a second-round effort of 59.22 metres.
Hogan was eliminated after three rounds, falling nearly three metres short of the midway cut.
Three-time world champion Robert Harting of Germany took the win with a best heave of 68.36m.
The next Diamond League meeting will be held in Oslo, Norway, on June 11.