MIAMI—The table is set here for the fourth round, traditionally the best—and certainly the meatiest—brace of days at any multi-week tournament. But split-sessions (day and night) and television schedules being what they are, we’ll get four WTA and four ATP matches today. The ones I find most intriguing are:

!PicSamantha Stosur (No. 6) vs. Serena Williams (No. 10): Second on the stadium, this is a re-match of last year's U.S. Open final, which was won by Stosur. That was Stosur’s first Grand Slam singles title, earned in her 34th attempt. Apparently exhausted by the long slog, she’s since collapsed.

Stosur has won two matches in succession at just one tournament this year (Doha) and had a first-round bye here. This is an excellent opportunity for Serena, who’s playing her first tournament since her fourth-round loss at the Australian Open, to get some payback. The head-to-head is surprisingly close; Serena leads by only 4-3, but I’m still going with her.

Na Li (No. 8) vs. Sabine Lisicki (No. 12): Is Li resurgent once again, and prepared to surprise us with the kind of tennis that earned her two Grand Slam finals (Australian and French Opens) last year?

Lisicki, who was ranked No. 175 at the start of 2011, has ridden her big serve and unbridled power game all the way back to No. 13, and seems intent on elbowing her way into the Top 10.

Given that Li is 30 and already given to inexplicable slumps, it’s a good opportunity for Lisicki. Given that the German has won both of their career meetings, this would be an upset only in statistical terms. I like Lisicki.

Mardy Fish (No. 8) vs. Kevin Anderson (No. 28): Fish is reeling. He has yet to win three matches at a tournament this season, and has beaten nobody ranked better than No. 28 in a completed match. In fact, coming into Miami, Fish had won just three completed matches (including a Davis Cup win) this year.

Anderson, by contrast, has won a tournament in 2012 (Delray Beach, where he defeated Andy Roddick and John Isner in back-to-back matches) and is just one of those nose-to-the-grindstone pros who’s made the most of his big but somewhat limited game.

Fish mastered Anderson in their only previous meeting, but we all know how spooked Mardy gets playing what amounts to a “home game” in the area where he grew up. For some reason, though, I think Fish will step up with his back so far against the wall and equal his previous 2012 output with his third win at this tournament.

Nicolas Almagro (No. 12) vs. Fernando Verdasco (No. 20): Okay, I’ll be writing a Racquet Reaction post on the Roger Federer vs. Andy Roddick match tonight. But given the way Federer is playing and their history, this slugfest is apt to be more dramatic.

Almagro has been playing excellent tennis, while Verdasco, ranked as high as No. 7 in 2009, is still trying to re-establish himself as a Grand Slam contender. Verdasco’s quarterfinal win over Almagro in Acapulco a few weeks ago was a big step in that process, and boosted his head-to-head record over his countryman to 5-2—all clay-court matches.

But given that Almagro has been in two finals this year (he won in Sao Paolo but lost the Buenos Aires final to David Ferrer) and was a quarterfinalist last week in Indian Wells, I’m going with him to advance in what ought to be a close, entertaining match full of teeth-rattling rallies.