Chad le Clos (Getty)
Rio de Janeiro - The battle has begun.
Chad le Clos and Michael Phelps have resumed the rivalry that started in London in 2012 - both of them safely through to the 200m butterfly semi-finals at the Olympic Aquatic Centre in Rio on Monday.
Le Clos won his heat in a time of 1.55.57 while Phelps finished third in his heat in 1.55.73. Overall, Le Clos qualified third-fastest for the semis while Phelps was fifth fastest.
Those times, of course, will not count for anything.
Le Clos, known for being one of the more media friendly athletes in South Africa, ducked straight past the scrum of hungry journalists waiting for him after his heat.
With Phelps' heat immediately after Le Clos', the possibility of having both heavyweights in the press area at the same time was tantalising.
However, it was not to be.
"I have to go cool down, guys. I promised my coach," Le Clos said before rushing off.
He does have a busy day.
On Monday night (Tuesday 04:19, SA time) he will swim in the 200m butterfly semi-finals while less than an hour earlier he will compete in the final of the 200m freestyle.
Le Clos is not expected to medal in the 200m freestyle having qualified seventh fastest for the final.
"It's a big day for me but I'm very excited for tonight," he said of the freestyle final once he had cooled down.
"I have been waiting a long time for this and I can't wait to race."
The rivalry with Phelps surely remains his priority.
While all eyes are on that rematch from London 2012, when Le Clos edged Phelps by 0.05 seconds to win gold, there is other stiff competition in the form of Laszlo Cseh.
The Hungarian won the fourth and final heat (1.55.14) to finish second-fastest behind his countryman Tamas Kenderes (1.54.73).
Lloyd Burnard is Sport24's correspondent in Rio de Janeiro for the duration of the 2016 Olympics ...