It happened a year ago in Melbourne when Azarenka -- in the midst of a mental breakdown that included smashed balls, five unfulfilled match points and screams unlike the kind we are accustomed to hearing from her -- opted for a medical timeout in her semifinal match with Stephens. It was, quite apparently, a panic attack.
It went on for nine minutes, and afterward, sufficiently gathered, Azarenka broke the 19-year-old Stephens for what, on paper at least, looked like a routine 6-1, 6-4 victory. It wasn't, especially when Azarenka spoke almost immediately after the match.
"I almost did the choke of the year right now," she told Channel 7 in an on-court interview. "I had so many chances, but I couldn't close it out. I felt a bit overwhelmed.
"I had to take a little bit of time to calm down."
A few minutes later, she told ESPN, "I couldn't breathe. It was like I was having a heart attack or something."
Some time later, that "something" morphed into a back injury and "locked" rib. Technically, it was within the rules, but the dubious circumstances sent the tennis universe into a feeding frenzy.
Patrick McEnroe, an ESPN analyst and the USTA's general manager of player development, called it an "absolute travesty" and Stephens' then-coach, David Nainkin, called it "unsportsmanlike" -- one of the worst things you can say about an athlete in this genteel sport.
We mention all of this because, thanks to the wonder of fully seeded Grand Slam draws, we have a potentially dramatic Sunday rematch. The No. 2-seeded Azarenka meets No. 13 Stephens in a fourth-round clash that could be as grim and competitive as those NFL conference championship games in Denver and Seattle.
"Definitely, it was a tough match," Stephens told reporters after winning her third-round match over Elina Svitolina. "Obviously, semis of a Grand Slam it was pretty intense. Looking forward to getting on the court again."
The key phrase: looking forward. Both Stephens and Azarenka invoked it three times each when questioned by reporters after their third-round matches. Stephens, particularly, took the high road.
Was too much made of the controversy?
"Who knows?" Stephens said. "That has nothing to do with this year. I don't even remember half the stuff that happened. It's OK."
Azarenka, too, was close to the ice vest.
"I have great memories of last year," she said after dusting Yvonne Meusburger 6-0, 6-1. "That's all I keep for me.
"We left it all last year here, and that's what's important for me, is to play another match. I'm just looking forward to that challenge."
There's that phrase again.
Both players agree that Stephens, now all of 20, is a better player in many respects. In the last year, she has become more of a professional.
"I'd say I don't get flustered as easily, something I have worked on," Stephens explained. "I don't get overwhelmed and I'm kind of learning to focus on myself, because that's the only thing I can control."
This observation has the fingerprints of Paul Annacone all over it. Always a cerebral player, Annacone guided Pete Sampras and, most recently, Roger Federer in the late stages of their careers. Stephens is a far different challenge; Annacone, a professor of advanced tennis, will have a hand in shaping her game and world view.
There were times last year when Stephens did not seem all that focused on the job at hand. Five times -- in Dubai, Indian Wells, Charleston, Madrid and Washington, D.C. -- she checked out in her first match. In the Grand Slams, however, Stephens has been startlingly sharp. This is the fifth consecutive major in which she has advanced to at least the fourth round, an impressive achievement considering her age and the increasing depth of women's tennis.
It's telling that she says, "My goal this year is to do better at the smaller tournaments."
In other words, the big ones will take care of themselves.
"I believe Sloane has the game [to win]," McEnroe said.
Azarenka will be a tough out. She has yet to drop a set, and she's trying to win three consecutive women's titles here for the first time since Martina Hingis (1997-99). You might say Azarenka owes Stephens one for taking out Serena Williams in last year's quarterfinals.
And we'll leave you with this:
Interestingly, the two athletes both have residences in Los Angeles and share the same agent. Stephens said she's never seen Azarenka in Los Angeles and describes their off-court relationship as "nonexistent."
Well, then, enjoy the match.