
The most successful female tennis player in the Open era. Serena Williams won her 23rd grand slam at Australian Open in January 2017 to eclipse Steffi Graf's record for grand slam titles in the Open era.

The American captured the title in Melbourne without dropping a set and is now one shy of the all-time grand slam total held by Margaret Court.

Williams defeated her sister Venus -- at 36 the oldest grand slam finalist in the Open era - in straight sets to claim her seventh Australian Open title.

But her achievements in Melbourne Park were made all the more remarkable when the tennis great announced in April that she and fiancee Alexis Ohanian (right) were expecting their first child "this fall."

Williams had posted a side profile shot of herself in a yellow swimsuit on Snapchat with a caption that read "20 weeks" before deleting it, later revealing she did not mean to post the picture.

Williams and Ohanian -- Reddit's co-founder --had also surprised fans in December by announcing their engagement. The pair had managed to keep their romance out of the spotlight.

News of Williams' pregnancy meant she had won the Australian Open while in her first trimester.

Williams will miss the rest of the season, having not played since the Australian Open, but says she will return to the WTA Tour next year.

The American appears to be enjoying her time away from the Tour, channeling her inner Na'vi during a sneak peek at Pandora - The World of Avatar at Disney's Animal Kingdom.

The tennis star has also been traveling the world. The mum-to-be was in Monaco last month for the F1 Grand Prix and was pictured with Red Bull duo Daniel Ricciardo (left) and Max Verstappen

In June, it was revealed that Williams was the only woman in the new Forbes list of the world's 100 highest paid athletes. Williams, ranked 51, made $27 million last year.

Williams in June also responded to John McEnroe's claims that she would struggle to be in the world's top 700 if she was on the men's Tour, telling her fellow American to "respect me and my privacy."