SINGAPORE — Martina Hingis announced Thursday that she will retire from tennis for the third time in her career at the end of the ongoing WTA Finals.

The Swiss initially confirmed the news on Twitter and Facebook after winning her quarterfinal doubles match. The top-seeded pair, Hingis and Chan Yung-Jan of Taipei, defeated Anna-Lena Groenefeld of Germany and Kveta Peschke of Czech Republic 6-3, 6-2.

“I told Latisha (Chan) from the start (of the year), ‘Hey this will probably be my last year,” Hingis said. “Probably people think after a season like this (to continue) but I think it’s perfect timing because you want to stop on top.”

“I couldn’t ask for a better finish.”

The 37-year-old Hingis amassed five Grand Slam singles titles, 13 Grand Slam doubles titles, and seven Grand Slam mixed doubles titles during her stop-start career.

Overall, she has won 43 singles and 64 doubles titles, and was one of six players to hold the No. 1 ranking in singles and doubles at the same time in her career.

This year, Hingis has won nine women’s doubles titles, including the U.S. Open with Chan. She also won the Wimbledon and U.S. Open mixed doubles trophies with Jamie Murray.

Hingis won last year’s WTA Finals doubles title with Sania Mirza of India.

Hingis first walked away from tennis in 2003 because of injuries.

She returned to the sport in 2006, but after testing positive for cocaine during the 2007 Wimbledon tournament she left the game again. Despite having already retired, in 2008 she was sentenced to a two-year ban from tennis for the positive drug test.

“The previous times (I retired) I always had things in the back of my head that I might be able to, singles and then doubles, might be able to do that,” Hingis said. “I think now it’s definite. Before I was thinking I might come back.”

In 2013, Hingis returned to tennis as a doubles-only player. She won 10 of her Grand Slam doubles titles since coming out of retirement in 2013.

“I’m looking forward to the things ahead of me, and tennis will always be a part of my life,” Hingis said, adding that “the travel will definitely be one thing I won’t miss anymore.”