Venus Williams is trying to get to the fourth round at the US Open for the first time since 2010 - and at any Grand Slam tournament for the first time since 2011.
To do so, the 19th-seeded Williams will need to beat 13th-seeded Sara Errani of Italy in Arthur Ashe Stadium on Friday. While Williams owns seven major singles titles, including two at the US Open in 2000 and 2001, Errani has had more recent success at tennis' most prestigious events.
In 2012, Errani was the runner-up at the French Open and a semifinalist at Flushing Meadows. She also was a semifinalist at Roland Garros last year. Pairing with Roberta Vinci, Errani completed a career Grand Slam in doubles by winning Wimbledon last month.
"She's so focused. She does everything well on the court clearly, because she's a great singles player and a doubles player," said Williams, who is 3-0 against Errani in previous singles matchups.
"Every time I've played her, I've had to be focused on every single point, because she does not let up on any point, no matter what the score is." The 6-foot-1 (1.85-meter) Williams holds significant advantages in height and power over the 5-foot-4 1/2 (1.64-meter) Errani.
"It's obvious that players who play that strong give me problems. They don't let me find my rhythm. They don't let me find my game," Errani said.
"Venus is tall, so the balls that I like to play to bother opponents - high shots with topspin - are perfect for her. So we'll see."
Other things to watch on Day 5 at the year's last Grand Slam tournament:
Known as a top returner, Maria Sharapova will need to contend with the owner of the fastest serve in women's tennis.
Five-time major champion Sharapova, seeded fifth this year, plays her third-round match at night against 26th-seeded Sabine Lisicki of Germany.
At a hard-court tournament in Stanford, California, in July, Lisicki hit the fastest record serve in the history of the WTA, reaching 131 mph (211 kph).
Lisicki beat Sharapova en route to reaching the Wimbledon final in 2013, but has lost all five of their other meetings.
"Should be a fun one," Lisicki said.
FEDERER VS GROTH
Roger Federer faces a big server at night, too, playing Australia's Sam Groth in the second round.
Groth, though, is only ranked 104th and has a losing career record of 10-15. He was 0-3 in Grand Slam matches until winning his first-round match at Flushing Meadows on Tuesday.
Federer, in comparison, is 973-224 for his career and owns a record 17 major championships.