New York - Caroline Wozniacki's sunny smile has never masked her deep determination, and the Dane has needed all of her grit to turn around the toughest season of her career.
She'll be hoping that a 6-4, 6-4 upset of 2004 champion Svetlana Kuznetsova in the second round of the US Open on Wednesday is a turning point in a 2016 campaign marred by injury and a precipitous drop in ranking.
Wozniacki, a former world number one, was two breaks down at 0-4 in the first set but won 12 of the next 16 games to advance.
"At one point, I was thinking we've being playing for 30 minutes. Right now, it's 4-0 for her, this is not looking good for me. I just kept fighting for every point."
The match could be a metaphor for her a 2016 season in which she missed three months nursing a right ankle injury.
Until arriving at Flushing Meadows she'd endured nothing but disappointment in the year's Grand Slams, falling in the first round in Australia and at Wimbledon and missing Roland Garros.
In characteristically optimistic fashion, Wozniacki said her enforced time off had an upside.
"When you're home for a big amount of time you realize that life goes on and you kind of get a rhythm at home," she said. "I was actually enjoying my time, making the most of the time that I had.
"I haven't been able to be home for three months in a row for the last probably over 10 years. So, you know, if I have to look at the positive of things, that was a positive."
Wozniacki sparked speculation she might be considering her non-tennis options with a "Letter to My Younger Self" on The Players' Tribune website last week.
"Tennis won't last for ever, Caroline," she counseled her 11-year-old self. "Plan for your future. Think about what you'd like to do next and take steps to set yourself up for a successful life after you play your last pro match."
But Wozniacki said Wednesday that she didn't feel that her tennis life was coming to an end.
"I always had in my head that I just have to keep working hard and I'll come back and hopefully play strong and play well," she said.
"I knew that it's not easy to come back, and especially, you know, you are going to get tough draws.
"I'm a player that needs matches to kind of get into the tournament. But I wasn't thinking about quitting."
Results from the third day of the 2016 US Open tennis
championships at Flushing Meadows on Wednesday (x denotes seeded player):
Novak Djokovic (SRB x1) bt Jiri Vesely (CZE) walkover
Mikhail Youzhny (RUS) bt Guido Pella (ARG) 6-2, 6-1, 7-6 (7/3)
John Isner (USA x20) bt Steve Darcis (BEL) 6-3, 6-4, 6-7 (10/12), 6-3
Kyle Edmund (GBR) bt Ernesto Escobedo (USA) 7-5, 6-4, 6-4
Jo-Wilfried Tsonga (FRA x9) bt James Duckworth (AUS) 6-4, 3-6, 6-3, 6-4
Kevin Anderson (RSA x23) bt Vasek Pospisil (CAN) 7-6 (7/3),
Jack Sock (USA x26) bt Mischa Zverev (GER) 6-1, 6-1, 6-2
Marin Cilic (CRO x7) bt Sergiy Stakhovsky (UKR) 6-1, 6-2, 6-3
Rafael Nadal (ESP x4) bt Andreas Seppi (ITA) 6-0, 7-5, 6-1
Andrey Kuznetsov (RUS) bt Albert Ramos (ESP x31) 7-5, 6-4, 7-6 (7/5)
Lucas Pouille (FRA x24) bt Marco Chiudinelli (SUI) 4-6, 3-6, 7-6 (8/6), 6-2,
Roberto Bautista (ESP) bt Federico Del Bonis (ARG) 5-7, 6-2, 6-3, 6-2
Gael Monfils (FRA x10) bt Jan Stral (CZE) 7-5, 6-4, 6-3
Nicolas Almagro (ESP) bt Pablo Cuevas (URU x18) 7-6 (7/5), 6-4, 7-6 (11/9)
Marcos Baghdatis (CYP) bt Benot Paire (FRA x32) 6-2, 6-4, 3-6, 6-4
Ryan Harrison (USA) bt Milos Raonic (CAN x5) 6-7 (4/7), 7-5, 7-5, 6-1
Madison Keys (USA x8) bt Kayla Day (USA) 6-1, 6-1
Naomi Osaka (JPN) bt Ying-Ying Duan (CHN) 6-4, 7-6 (7/3)
Monica Niculescu (ROM) bt Ana Bogdan (ROM) 6-0, 6-1
Caroline Wozniacki (DEN) bt Svetlana Kuznetsova (RUS x9) 6-4, 6-4
Johanna Konta (GBR x13) bt Tsvetana Pironkova (BUL) 6-2, 5-7, 6-2
Belinda Bencic (SUI x24) bt Andrea Petkovic (GER) 6-3, 6-2
Kateryna Bondarenko (UKR) bt Zheng Saisai (CHN) 5-7, 7-6 (7/5), 7-5
Anastasija Sevastova (LAT) bt Garbie Muguruza (ESP x3) 7-5, 6-4
Roberta Vinci (ITA x7) bt Christina McHale (USA) 6-1, 6-3
Carina Witthoeft (GER) bt Yulia Putintseva (KAZ) 6-1, 6-7 (1/7), 6-1
Lesia Tsurenko (UKR) bt Wang Yafan (CHN) 7-5, 6-3
Dominika Cibulkova (SVK) bt Evgeniya Rodina (RUS) 6-7 (5/7), 6-2, 6-2
Petra Kvitova (CZE x14) bt Çagla Büyükakçay (TUR) 7-6 (7/2), 6-3
Elina Svitolina (UKR x22) bt Lauren Davis (USA) 6-1, 4-6, 6-3
CiCi Bellis (USA) bt Shelby Rogers (USA) 2-6, 6-2, 6-2
Angelique Kerber (GER x2) bt Mirjana Lucic-Baroni (CRO) 6-2, 7-6 (9/7)