While Angelique Kerber was winning her third straight match at the WTA Finals, she glanced courtside and noticed three famous spectators in the crowd — Chris Evert, Martina Navratilova and Monica Seles.

Kerber, ranked No. 1 in the world and a two-time Grand Slam champion, took it as a sign that she has really arrived.

"I just looked once over there, and all the great legends and champions, they are sitting there," Kerber said. "Of course it's a great feeling that I'm on court and they are watching me. Now I can say I am one of those players that won Grand Slams and being the No. 1 player in the world."

In a year that marks a full decade of Kerber playing on the tour, the German's banner 2016 season has taken her to the top of the sport.

Kerber beat then No. 1 Serena Williams in the Australian Open final for her first major title in January, and downed Karolina Pliskova at the U.S. Open last month for her second Grand Slam championship. In between, she reached the Wimbledon final, losing to Williams, and won an Olympic silver medal in Rio de Janeiro.

Kerber joins Evonne Goolagong Cawley, Steffi Graf and Martina Hingis as the only female players in the Open era to reach three Grand Slam finals in a season.

To top it off, the 28-year-old Kerber became the oldest player to reach the No. 1 ranking following her U.S. Open triumph.

"The first special moment was in Australia when I won my first Grand Slam," said Kerber, recounting her magical season in Singapore. "This feeling I will never forget. Also, with New York this was really special tournament for me in my career where everything starts in 2011 (she reached the 2011 semifinals). Olympics as well. I was always dreaming to win a medal.

"I had a lot of great moments this year," she added.

Kerber ended the previous four seasons in the top 10. But 2016 delivered a more focused, determined and experienced competitor.

"I think for me it's also good that I'm in this age right now where I can really enjoy it," Kerber said. "I had so many experiences from the last few years, and now I'm just trying to enjoy, but still work hard."

Agnieszka Radwanska finds inspiration in Kerber's incredible season.

"I think Angie showed everyone, all of us, that it's possible," Radwanska said. "You can beat Serena, also in a Grand Slam final. She definitely proved that everybody can be on the top."

Kerber is showcasing her strengths at the WTA Finals, where she has won all three of her round-robin matches to reach the semifinals of the year-end tournament. In her three previous appearances at the finals, she had failed to advance past the round-robin stages.

"It's completely different feeling right now," Kerber said. "Now I know how to go out there with all the pressures I have on my shoulders. I know how to play and how to focus on what I'm doing on the court."

"It doesn't matter who I'm playing or like what the score is or how the situation is," she added. "I think I learned a lot in the last few months. Doesn't matter if it's the first or last round, I'm just going out there to play my game."