Opinion: The first Angelique, not the second Steffi

Respect! Angelique Kerber has succeeded in achieving what only Steffi Graf had done before her: She is the new No. 1 women's tennis player. And rightly so!

To describe this as a fleeting moment of success or to put it down to the weakness of the dominant player of recent years, Serena Williams, would be wrong. Kerber may not be the most talented or most consistent tennis player in the world. She has improved her serve, but hers is still far from the best. But after a number of first-round defeats, Kerber has shown that technique can be improved and that setbacks don't keep her down. On the contrary, they have made her stronger. Though ambition, fighting spirit and newly found mental toughness Kerber has achieved what few thought she could: She has made it to the very top.

Many observers wrote her off as a "one-hit wonder" when she was knocked out in first round in Roland Garros, the next Grand Slam after her victory at the Australian Open. It can take time for an athlete to adjust to the heightened expectations that come with being a Grand Slam champion. However, adjust Kerber did. She came back from setback to make this a year in which she reached three Grand Slam finals (Australian Open, Wimbledon, US Open) and the final of the Olympic tournament in Rio.

The long shadow cast by Steffi Graf

So Kerber has finally proved herself, but here is no escaping the long shadow cast by another big name, that of Germany's former tennis goddess, Steffi Graf. Graf played her way into German hearts and onto almost every German's television screen at a time when there was no precedent. Along with Boris Becker, she set off a tennis boom in West Germany that will not be repeated despite Kerber's success.

And nobody should expect Kerber to do so either. There are other talented German women, such as Andrea Petkovic, Julia Görges or Sabine Lisicki. But only Kerber has managed to step out of Graf's shadow, first by winning a Grand Slam, then by becoming the new No. 1.

Despite this, Kerber will never be able to approach the greatness of Steffi Graf. At 28 Kerber is the oldest woman to reach No. 1 since the rankings were introduced, while both Graf (18) and Serena Williams did so at a much earlier age. Kerber's age makes it all the more impressive that she has completed her climb to No. 1.

Tennis is very much a mental game, and Kerber struggled with this facet of the sport for a long time. But she has overcome this weakness, thanks to many conversations with Graf, her prominent predecessor. Her new mental toughness was on display in Thursday's semifinal, when she took to the court known that the No. 1 ranking would be hers on Monday, no matter what the outcome.

Instead of being distracted by the news, she looked relaxed as she delivered outstanding tennis in the US Open semifinal against her close friend, Carolina Wozniacki, who happens to be a former top-ranked player. The Dane didn't stand a chance. Kerber delivered a match and victory worthy of the new No.1. Two days later she battled her way to a 6-3, 4-6, 6-4 victory against Karolina Pliskova to win her second Grand Slam title.