Before each day's play at Flushing Meadows, we'll preview and predict three must-see matches.

Young will have good memories of playing this opponent at the Open; his win over Wawrinka in a fifth-set tiebreaker here in 2011 was the biggest of his career at the time. But DY’s memories of playing in Ashe Stadium won’t be as rosy. He acquitted himself honorably in a five-set night-match loss to James Blake in 2008, but was dismissed quickly by Roger Federer, in another night session, in 2012. This fourth-rounder is during the day, but it should draw a vocally pro-DY Labor Day crowd anyway. Still, there are a few reasons to believe that his fairytale run, which includes two comebacks from two sets down, will come to an end. After playing on Court 17 and the Grandstand, it might be tough for him to adjust to the vastness of Ashe. Wawrinka is not the same player he was when they met four years ago—he's much better. And at some point, the many hours Young has spent on the court will have to take their toll. Winner: Wawrinka

Don’t look now, Serena Williams, but there’s another woman on a tear: Konta, a 24-year-old Aussie turned Brit, has won 16 straight matches since losing in the first round at Wimbledon. She’s ranked just 97th, but this week she’s beaten two players who have spent time in the Top 10, Garbiñe Muguruza and Andrea Petkovic, on her way to becoming one of the stories of the tournament. Now Konta will face another Top Tenner in Kvitova. The Czech hasn’t cottoned to Queens in the past, but she has cruised so far this year, winning all six sets she’s played. She seems to be treating her trip to New York like a beach vacation, and maybe that’s helped; whether it continues for another day will be up entirely to her. These two have never played. Winner: Konta

The Open and ESPN got the Labor Day match-up they wanted: Federer vs. the top American. Oddly, the network has chosen to schedule it not during afternoon BBQ hour, but late in the evening. That may hurt the home-country boy, who likes his serve to bounce high in the heat. As for Federer, no matter what form he may be in right now—and it’s a pretty fine one—this promises to be a test for him. With his serve, Isner can render his opponent’s level of play meaningless, and sets may be decided by a single mishit. Still, Federer knows his way around a breaker, where he's almost certain to end up at some point tomorrow, and he has managed to impose his will on Isner in most of their meetings. He’s leads their head to head 4-1; Isner’s sole victory came, of all places, on clay in Switzerland during a Davis Cup tie. Can Isner repeat that performance in front of a friendlier crowd, and on what should be a more comfortable surface for him? Just as intriguing, will Federer dare to try his SABR return of Isner’s towering kick? Winner: Federer