? Steffi Graf: Women's trailblazer

Djokovic was barely 3 months old when Graf became women's world No 1 for the first time in August 1987.

The German star was just 18 and would remain on top of the pile in her first spell for 186 weeks.

It was a landmark moment in the women's game as it came the day after Graf had won the first of her 22 majors at the French Open.

She was also the first woman outside of Martina Navratilova, who had held top spot for 322 weeks, and Tracy Austin in seven years to ascend to the No 1 ranking.

Graf, who won 107 career titles, retired in August 1999.

AFP