NEW YORK -- Will Sofia Kenin walk out onto Arthur Ashe Stadium to play Maria Sharapova wearing multicolored tennis shoes with the word "believe" written on them? That's what the then-17-year-old Melanie Oudin did during an astonishing run that carried the virtually unknown Marietta, Georgia, native, ranked No. 70, to a win over Sharapova and ultimately all the way to the 2009 US Open quarterfinals.
Kenin, an 18-year-old Floridian, is a wild-card entry who's beaten No. 32 seed Lauren Davis and 22-year-old qualifier Sachia Vickery.
Sharapova and Kenin have no history, but the latter will probably have to play the match of her life in order to win. Sharapova seems dialed in and match-tough despite having played just 10 completed matches since returning in April after a 15-month doping suspension.
In yet another twist, Oudin herself retired a little over a week ago, at age 25, citing a series of injuries that began to plague her late in 2012. She made her retirement announcement in a series of tweets, writing, "It wasn't exactly the entire career I had dreamed of, but in life things don't always go as planned."
Here are some other compelling third-round matches:
United Nations match of the day
Like so many players these days, 22-year-old Kyle Edmund and 18-year-old Canadian sensation Denis Shapovalov were globetrotters from birth.
Edmund was born in South Africa, but emigrated to and plays for Great Britain. Shapovalov was born to Russian parents in Tel Aviv, but is a Canadian who now calls Nassau, Bahamas, home. Not to worry, northern friends, Shapovalov still loves the Toronto Maple Leafs!
Shapovalov crushed fellow #nextgen pro Daniil Medvedev and No. 8 seed Jo-Wilfried Tsonga, while Edmund eliminated No. 32 Robin Haase and Steve Johnson in his first two matches.
The series is tied at 1-1, with both encounters this year. The southpaw Shapovalov eked out a 6-4 in-the-third win on grass at Queens Club this summer. Earlier this year, Edmund was rolling with a two-sets lead in a Davis Cup tie when Shapovalov retired with an injury.
Gorgeous scorecard
These days, most of the oxygen in tennis is sucked up by 30-and-over veterans enjoying unexpected, continuing success -- or the latest, greatest hard-charging prodigies. Where does that leave players like No. 78 Aleksandra Krunic or No. 30 seed Julia Goerges?
Answer: In the third round of the US Open, thanks to impressive wins so far. Krunic dumped No. 7 seed Johanna Konta and fellow 24-year-old Ajla Tomljanovic. Goerges has lost a grand total of just four games in her two previous matches. She also won her only previous encounter with Krunic.
Suddenly, Sam
Sam Querrey appears to have turned around his reputation as a "soft" contender when he battered his way to the semifinals of Wimbledon. Instead of experiencing a letdown (a familiar enemy), Querrey won a tournament (Lo Cabos).
The 6-foot-6 Californian, seeded No. 17, drew a tough first-round opponent in Gilles Simon, who can run anyone to the ground. But that big serve and forehand, along with a re-tooled backhand, have served Querrey well. He has yet to lose a set, and he's unlikely to drop one when he meets his next opponent, Radu Albot.
A Moldavian, Albot is a 27-year-old qualifier who had just two Grand Slam singles wins to his credit before he advanced to the third round with back-to-back five-set wins. On the horizon for Querrey: a potential fourth-round clash with familiar face, No. 10 seed John Isner.
Has Stephens hit the reset button?
As Roger Federer can attest, sometimes a long break from the game -- for any reason including injury -- is just what the proverbial doctor ordered for a stalled player. Sloane Stephens seems to have bought into the message.
Sidelined for nearly a full year with a right foot stress fracture that required surgery, she lost early at Wimbledon and Washington D.C. But then she caught fire, making the semifinals at the two big summer hard-court events, Toronto and Cincinnati. Stephens has a promising draw, with Ashleigh Barty next. This is close to a must-win match if Stephens, now 24, is going to realize her much-celebrated potential.
Long, like those spaghetti westerns
Fans from Brindisi to Genoa will thanking their lucky stars that the US Open employs a fifth-set tiebreaker when Thomas Fabbiano meets Paolo Lorenzi. Fabbiano, 28, hadn't won a Grand Slam singles match until this week; Lorenzi, 35, has come this far at just one other major in 25 previous tries. Both men survived knock-down, drag-out matches here, accounting for 17 sets, including five tiebreakers. But they have never played each other as pros. Order a large pizza and a liter-sized bottle of whatever if you plan to watch this one.
Most intriguing match of the day
Petra Kvitova, seeded No. 13 and still in the midst of her comeback, plays No. 18 seed Caroline Garcia. It says something about this draw that it's one of just two matches between seeded players at this stage in the bottom half of the draw.
This series is tied at 2-2. Garcia, a late bloomer from France, won the past two meetings. Kvitova is still recovering from her hand injury, but she's a two-time Wimbledon champion. This one screams barnburner.