Sunday was all about the Williams sisters – Venus and Serena – setting up a cannot-miss-it-for-the-world 2015 US Open quarterfinal. Monday is about the two big guns in the men's singles – Roger Federer and Andy Murray – and if they can do what the other main man – Novak Djokovic – did on Sunday, by moving into the last eight.
Federer has played as good as anyone so far in this US Open, beating all three of his opponents in straight sets.
The 17-time Grand Slam champion's fourth round opponent is going to be the trickiest yet – because not only does John Isner have the power game to cause an upset, he will have the crowd support as well -- well as much as the crowd can possibly go against the immensely-loved Federer, that is.
Isner hasn't dropped a set in this US Open either, with the American only having to play two sets in his previous match, as Jiri Vesely retired early.
The other big match in the men's singles on Monday is Andy Murray vs Kevin Anderson. Murray has not been at his best in this tournament, but he has shown that fighting spirit that separates the champions from the rest, even coming back from two sets down in the second round.
Having struggled with illness in the first week, Murray will hope his health and form returns to devastating effect against Anderson, who, like he showed in that marathon match in Wimbledon against Djokovic, has the capabilities to cause an upset.
French Open champion Stanislas Wawrinka plays home favourite Donald Young, while the fourth round clash between Tomas Berdych and Richard Gasquet should provide some fireworks as well.
In the women's draw, Victoria Azarenka will want to stay on course for that possible final with Serena, with American Varvara Lepchenko her fourth round hurdle. Samantha Stosur vs Flavia Pennetta should be an interesting match, while Johanna Konta will look to continue her giantkilling ways when she plays two-time Wimbledon champion Petra Kvitova.
The No.2 seed Simona Halep will hope to overcome the powerful, if inconsistent, game of Sabine Lisicki.
In Indian interest, Rohan Bopanna, and his men's doubles partner Florin Mergea, open up play at the Louis Armstrong Stadium with their third round match against Daniel Nestor and Edouard Roger-Vasselin.
Leander Paes and Martina Hingis, the mixed doubles Wimbledon champions, are over on the Grandstand Court, where they have to overcome Romanian duo Halep and Horia Tecau in the quarterfinals.
US Open Day 8 Schedule and Order of Play: Arthur Ashes Stadium (Play starts 11 am local time, 8.30 pm IST, 4 pm BST) Women's singles: Fourth round: Varvara Lepchenko (USA) vs 20-Victoria Azarenka (Blr)
Men's singles: Fourth round: 5-Stanislas Wawrinka (Sui) vs Donald Young (USA)
Women's singles: Fourth round: 22-Samantha Stosur (Aus) vs 26-Flavia Pennetta (Ita)
Night session: (Play starts 7pm local time, 4.30 am IST, 12 am ET): Women's singles: Fourth round: 5-Petra Kvitova (Cze) vs Johanna Konta (GB)
Men's singles: Fourth round: 13-John Isner (USA) vs 2-Roger Federer (Sui)
Louis Armstrong Stadium (Play starts 11 am local time, 8.30 pm IST, 4 pm BST): Men's doubles: Third round: 6-Rohan Bopanna (Ind)/Florin Mergea (Rou) vs 9-Daniel Nestor (Can)/Edouard Roger-Vasselin (Fra).
Women's singles (Not before 12.30 pm local time, 10 pm IST, 5.30 pm BST): Fourth round: 24-Sabine Lisicki (Ger) vs 2-Simona Halep (Rou)
Men's singles: Fourth round: 15-Kevin Anderson (RSA) vs 3-Andy Murray (GB)
6-Tomas Berdych (Cze) vs 12-Richard Gasquet (Fra).
Grandstand (Play starts 11 am local time, 8.30 pm IST, 4 pm BST): Mixed doubles: Quarterfinals: Simona Halep (Rou)/Horia Tecau (Rou) vs 4-Martina Hingis (Sui)/Leander Paes (Ind). Note: This is the fourth match on the Grandstand Court.
The full order of play for Monday is HERE