He leads his country out for a world-record 36th time and would only continue at the top if the Springboks win.
Based on world-record times for similar distances, cycling would take 54% of race time, running 31%, and swimming 15%.
We are required to run a mile in world-record time with no running allowed.
Cram had run his world-record time of 3:46.32 on the same track in 1985.
In his third event, the 100-meter butterfly, Phelps won with a world-record time of 50.22.
It also struck all his results since 2001 from the records, including a then world-record time of 9.78.
But the gap was much too great to close, and Rudisha crossed the line in a world-record time of 1:40.91.
He previously won the races at 1,500 and 5,000 meters in world-record time.
According to a 2001 media report, the world-record time for this course setup is 38 seconds.
Then, less than 48 hours later, he proceeded to win the second of his three straight titles in world-record time.