Lleyton Hewitt, the former world men's No 1, asked Kim Clijsters, the women's No 2, to marry him as they took a romantic boat ride around Sydney Harbor.
"He invited me for dinner on a boat and suddenly unveiled a ring and earrings," Clijsters, who is Belgian, told her official web site. "I didn't know what hit me, but I'm very happy about it. In Australia, being engaged means a lot. I'm extremely happy with my early Christmas present."
Hewitt's management company, Octagon, has confirmed the engagement but said no date had been announced. "Lleyton did surprise me a bit but I couldn't be happier," Clijsters, 20, said. "He has always been one to pay great attention to detail but I think he out-did himself this time."
Hewitt, 22, said: "It was a special evening together in one of the most beautiful cities in the world." The pair announced they were dating in the middle of 2000 at the French Open and two weeks later played the final of the Wimbledon mixed-doubles.
They have been drawn to play against each other for their respective countries at next month's Hopman Cup in Perth. That tournament is part of their preparation for next month's Australian Open.