Olivier led the field for most of the second lap, but faded in the chase for the line in the men’s 800m event, holding on for third place in a season’s best 1:44.85.
“It wasn’t a bad race. I’m happy with the time and place, and the last 60m will come,” he said.
In a similar finish, Van Zyl was well placed in the 400m hurdles but struggled after the final barrier and took fourth place. Regaining his best international form since his magnificent 2011 campaign, Van Zyl clocked a respectable 48.97.
“It was a good personal victory for me although I was fourth,” he said.
“At the last hurdle I lost a bit of rhythm, so I just need to work on my race fitness.”