19-time Grand Slam winner Roger Federer says his success is partly down to compatriot Martina Hingis, who announced her intention to retire this week.
"Martina was partially the one who showed me how it was all done," he said on hearing the news. "It was great for Switzerland to have someone of her calibre. We were very lucky. I loved playing with her at the Hopman Cup, she was always super friendly, I love that about her."
The pair won the 2001 Hopman Cup together - Federer's first professional title.
But he says he is not sad to see her step away from the game.
"I’m not sad to see her retire, she’s been in the game for long enough, she seems at peace with her decision – that’s wonderful. I’ve always been a fan of her and I always will be."