And he was followed during the course of the evening by Khotso Mokoena in the triple jump, Rocco van Rooyen in the javelin and then the 4x100m relay team.
Cronje ended third behind dangerman Ronald Kwemoi of Kenya (3:39.40) in 3:40.17 with the first four booking their place in the final.
Cronje went off in the second of two heats (effectively semi-finals), along with 11 rivals.
Going into his round, apart from Kenyan Ronald Kwemoi (3:28.81) he was the fastest man in his heat this season with a 3:33.31 clocking.
At 30 years of age he was also the oldest man of the 25 athletes
entered into the heats.
"I was never stressed in this one,’ he said afterwards, after loping along in around 10th spot for the opening half. Then with just over 600m to go he moved up smoothly down the back straight to hit the front and keep the pace honest.
"I just wanted to stay out of trouble because its often with around 500-600m to go that the pushing and bumping starts.
"I was fortunate to run the second heat so knew what the first heat’s times were and what I had to do."
Looking ahead to Saturday’s final and Cronje said it’s going to be ‘tough’.
"The Kenyan guy (Kwemoi) that won my heat will be one to watch, Nick Willis, even the Scottish guy Chris O’Hare with home town support."
He then went on to predict a winning time of ‘around 3:38-40, well that’s my feeling. I reckon the first half will be quite slow and then we’re going to have a fast second half.
"Hopefully I have left my 'fast' race for here. Quite a few of the guys here ran pretty quickly in Monaco a few weeks back but I’m hoping this will be mine. Unfortunately, unlike some of the other guys, I don’t tend to run many quick races within the space of a short time."
The first heat was won by Kiwi Nick Willis in 3:40.76.
Mokoena was next to book his place and he needed just one impressive jump to take him through. A 16.69m effort was his opening and that was all he needed.
"I just wanted a 16.40m to get me through."
The last time the former Olympic long jump silver medallist did the triple jump at this level was a long eight years ago. ‘That was at the Melbourne Commonwealth Games.’ he laughed. I did it at national level this year but not at this high international level. It’s coming back bit by bit, the triple jump.
"There’s still plenty in the tank for tomorrow. The trick is just to take it day by day and get the job done.
Thanks to God and my coach Emmarie Fouche, we’re getting there."
Then it was Van Rooyen in the javelin. He needed a 78m to go through automatically and opened with a 71.55. He improved that to a 72.79 and his third and final effort was a 77.57, which was still good enough to put him among the top 12 throwers.
"It took me a while to get the rhythm going," said the youngster.
"My arm was a little bit high but the armspeed is good.
"I took a longer run-up for my third row and that helped. Tomorrow I need to be a lot more explosive and start more like I finished today. I know I can unleash a bomb."
Pushed for what it will take to medal he said: "I’d say a win would take around 83-84m, silver about 82-83 and then a podium around 79.80.
"The good thing is that my injuries are staying away for the main. My elbow is still a bit sore but it’s better when it warms up."
Final SA participation of the night saw the men’s relay team go directly into the final, courtesy of a second placed finish in the third and final heat.
The first two teams in each heat went through automatically and the next two fastest teams joined them.
Trinidad and Tobago won the first heat in 38.33, then Olympic legend Usain Bolt anchored Jamaica to victory in the second heat (38.99).
Then it was the turn of Hendricho Bruintjies, Simon Magakwe, Ncincilili Titi and Akani Simbine to show their stuff. They had a fluid team effort, taking a comfortable second in 38.91 behind England (38.78).
Said elder statesman Magakwe: ‘It was an awesome experience. The first job was just to qualify. Our changeovers can definitely improve but our main mission tomorrow is just to get on to that podium.