Caroline Wozniacki took to Twitter to announce her engagement to NBA star beau David Lee on Saturday morning.
Caroline Wozniacki had won just one set from seven harrowing defeats to Venus Williams.
Wozniacki was furious that her second round match was played on an outside court while five-time major winner Sharapova was playing all of hers in Arthur Ashe Stadium.
Five tennis players have a chance to grab the world No 1 ranking at this week's Cincinnati Open.
Roger Federer hit his 10,000th career ace in the eighth game of the first set.
Novak Djokovic clinched his first title since January with a 6-3, 6-4 victory over Gael Monfils.
The tournament will already be underway when five-time Grand Slam champion Maria Sharapova's suspension ends on April 26, and she'll play her first match that day.
Rafael Nadal needed all his trademark grit against Alexander Zverev, 19, dubbed "the future of tennis", and his superior fitness told as he ground out a thrilling 4-6, 6-3, 6-7 (5/7), 6-3, 6-2 win
Both Johanna Konta and Caroline Wozniacki are angling for a maiden Grand Slam title with the winner of their clash on Saturday potentially facing sixth seed Dominika Cibulkova in the Australian Open fourth round and Serena Williams in the quarters.
Dominika Cibulkova hardly broke a sweat as she breezed past Germany's World No.31 Laura Siegmund while Caroline Wozniacki dumped Olympic champion Monica Puig out of the Sydney International
The 1-6, 6-3, 6-4 defeat of Caroline Wozniacki, the Danish third seed and former world number one, eliminated the last of the WTA Auckland Classic drawcards, a day after the exit of the two top seeds Serena and Venus Williams.
Caroline Wozniacki weathered an early storm from her teenage opponent before running out a comfortable winner, claiming a second Pan Pacific Open title and the 24th of her career
Caroline Wozniacki, a winner in Tokyo six years ago, will face either Ukrainian, Elina Svitolina, or Japan's Naomi Osaka in Sunday's Pan Pacific Open final as she goes in search of a 24th career title
It will be Karolina Pliskova's first appearance in a Grand Slam final while Australian Open champion Angelique Kerber will be in her third of the year.
German second seed Angelique Kerber will take on Czech Karolina Pliskova in the US Open women's singles final on Saturday.
With World No.2 Angelique Kerber also through to the US Open semis, Serena Williams must at least make it to the final to extend her reign atop the world rankings to a record 187th week
Caroline Wozniacki's father Piotr had been quoted in national media as suggesting that his daughter was unlikely to play beyond next year
Caroline Wozniacki, who beat Anastasija Sevastova in the quarterfinals, will face second seed Angelique Kerber in the US Open women's singles semifinal