Serena Williams has been less than impressive to-date (Getty)
Serena Williams is just four matches of US Open tennis away from a first Calendar Grand Slam in over 25 years as she squares up against fellow American Madison Keys in the early evening game on Arthur Ashe. Keys could prove a real test for Williams, who’s looked a little shaky in both of her previous ties: “She has a good return. She has a heavy shot. She’s moving well,” Williams said of Keys, and she’s not wrong. Keys’ groundstrokes so far this championship have actually averaged 7mph faster than Williams’, while her fastest serve at Flushing Meadow this week is only a couple mph shy of the woman who, in coach Patrick Mouratoglou’s opinion, has the greatest serve ever to grace the women’s game.
Elsewhere, World No.1 Novak Djokovic plays Spaniard Roberto Bautista Agut in the 7pm game, while Eugenie Bouchard is last up on Louis Armstrong, facing unseeded Italian Roberta Vinci. For a full rundown of the order of play for Sunday, click here.
In the US, ESPN3 has live coverage from 11am Eastern through until 11pm, with additional coverage on ESPN (1pm – 6pm) and ESPN2 (6pm – 11pm) throughout the day. The Tennis Channel has highlights throughout the night from 11pm.
In the UK, Sky Sports 1 has full live coverage of the day’s play from 4pm BST, through until 4am. British Eurosport also has live coverage from 3:45pm BST.
Across Europe, Eurosport has live coverage from 4:45pm CET.
If you can’t get in front of a TV, here’s how to watch online and on mobile:
Watch US Open Tennis Online
Madison Keys keeps her eyes on the prize (Getty)
In the US, if you have the log-in info for a cable subscription with access to Watch ESPN, you can watch the day’s play at WatchESPN.com. You’ll need a cable log-in and password, or the log-in and password of someone you know, to access the stream.
In the UK, viewers with access to a satellite subscription can watch the tennis online through Sky Go. You’ll need the log-in and password for a satellite subscription — either yours or someone else’s — to access the stream.
Across Europe, viewers with a Eurosport Player subscription will be able to watch here.
Watch US Open Tennis on Mobile
Novak Djokovic pulls his winning face (Getty)
Mobile and tablet users with access to Watch ESPN can watch the tennis on the Watch ESPN app. As is the case with desktop, you’ll need the log-in for a cable subscription with access to ESPN. You can download the app for free in the App Store or Google Play store.
Mobile users in the UK can watch the day’s play on the Sky GO app, which is free to download from the App Store or Google Play store. You’ll need a satellite subscription and log-in details to access the stream.
Across Europe, you can watch every day’s play via the Eurosport Player App, which you can download in the App Store or the Google Play store. Again, you’ll need a subscription to watch.