Aryna Sabalenka was in trouble Wednesday afternoon, down 1-4 in the third set to Sloane Stephens at the Omnium Banque Nationale presente par Rogers.

In years past, Sabalenka sometimes lost her poise in moments of turbulence, but 2021 has revealed a new resolve. After failing to reach the quarterfinals of a major in 13 previous attempts, the 23-year-old from Belarus sailed into the semifinals at Wimbledon. Earlier, she won titles in Abu Dhabi and Madrid, where she beat World No.1 Ashleigh Barty in what felt like a career-changing moment.

Sabalenka rallied to win the last five games of her match with Stephens, playing some terrific points down the stretch, punctuated by a pin-ball battle of volleys.

Thus, the No.1 seed survived and advanced to Thursday’s Round of 16, which features some intriguing matches.

TOP HALF

No.1 Aryna Sabalenka vs. Rebecca Marino

Tennis Canada handed out wildcards to former Grand Slam champions Simona Halep and Sloane Stephens and three Canadians – Leylah Fernandez, Carol Zhao and Rebecca Marino.

Marino, a 30-year-old who was born in Toronto, has wildly defied expectations, knocking off No.16 seed Madison Keys and, on Wednesday, No.31 Paula Badosa. Marino, ranked No.220, dropped the first set but mounted an epic comeback to win 1-6, 7-5, 6-4.

Aryna Sabalenka

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Her reward? A date with Sabalenka.

READ: Sabalenka overcomes Stephens in Montreal; Konta scores first win over Svitolina

Hard to believe, but less than a month ago, Marino played – and won – the $25,000 event in Evansville, Indiana. Ranked a career-high No.38 a decade ago, she was one of the first players to talk openly about the difficulties of being a professional athlete. Shaken by anxiety and depression, she retired in 2013 at the young age of 22. Marino returned to the tour in 2018 with a renewed passion for the sport.

“I think it was the right decision at the time for me to step away from the game,” she said after beating Keys. “I know some people didn’t understand it at the time, but I’m really proud of the decisions I made because it made me feel like a completely whole individual, and it made me rediscover my love and passion for the sport.

“I think it shows when I play. I think it also shows that I’m in a completely different headspace now because I did take that time to sort of make sure that I was taking care of myself, staying healthy mentally, physically, then come back into the game when I was ready.

Head-to-head: 0-0.

No.8 Victoria Azarenka vs. No.11 Maria Sakkari

Azarenka made short work of Sorana Cirstea in her first match, 6-2, 6-2. This is the same player Azarenka lost to in her most recent previous match, in the second round at Wimbledon. The 32-year-old from Belarus is 16-5 on the season and reached semifinals in Berlin and Doha.

Sakkari’s beaten Marie Bouzkova and Veronika Kudermetova on Wednesday – 6-4, 5-7, 6-4 – to reach the round of 16. The 26-year-old from Greece is 26-12 for the year and had a breakthrough performance at Roland Garros, beating Sofia Kenin and defending champion Iga Swiatek to reach the semifinals, where she lost to eventual champion Barbora Krejcikova.

READ: Pliskova, Sakkari survive gruelling encounters to reach Montreal third round

Head-to-head: 1-0, Azarenka, a winner in the 2020 Ostrava semifinals, 6-1, 6-3.

No.4 Karolina Pliskova vs. Amanda Anisimova

Two years ago, Anisimova was a 17-year-old semifinalist at Roland Garros.

Lately, it’s been a struggle, starting with a case of COVID-19 back in January. Since then she’s had modest results, including quarterfinals appearances in Bad Homburg and Parma. And now, after defeating a pair of fellow qualifiers, Tereza Martincova and Oceane Dodin, the 19-year-old American faces Pliskova, the 2021 Wimbledon finalist.

“I really want to have a good run here,” Anisimova said. “I think I’m ready for that. I think my game is there. I’m feeling good physically and mentally. Yeah, something to finish off the season pretty well.”

Pliskova rallied to defeat Donna Vekic 4-6,6-3, 7-6 (2).

Head-to-head: 2-0, Pliskova (2018 Indian Wells, 2019 Wuhan), both in straight sets.

Sara Sorribes Tormo vs. Katerina Siniakova

Based on the available data, this unseeded matchup is a tossup.

Sorribes Tormo, 24, is ranked No.48, while the 25-year-old Siniakova is No.55. Sorribes Tormo won her first career title, in Guadalajara, back in March and beat Jennifer Brady, Elena Rybakina and Ons Jabeur to reach the quarterfinals in Miami.

Siniakova teamed with fellow Czech Republic player Barbora Krejcikova to win the gold medal in Tokyo. Tuesday, she upset No.5 seed Garbiñe Muguruza 6-2, 0-6, 6-3, her second Top 10 win of the season after beating Serena Williams on the clay in Parma.

Head-to-head: 1-1. Siniakova won the most recent meeting in late June, in the Bad Homburg semifinals.

BOTTOM HALF

No.7 Petra Kvitova vs. Camila Giorgi

Kvitova, a two-time Grand Slam singles champion, dispatched Fiona Ferro 6-4, 6-4, while Giorgi handled Nadia Podoroska 6-2, 6-4.

A winner in Doha, Kvitova is now 21-12 for the season. Giorgi, who knocked off No.9 seed Elise Mertens in the first round, is 19-12 this year.

Head-to-head: 1-1. Most recently, Giorgi won in the Round of 16 at 2018 Sydney).

No.15 Coco Gauff vs. Johanna Konta

Konta authored the upset of the tournament so far, defeating No.3 seed Elina Svitolina 3-6, 6-3, 6-2. Gauff advanced when qualifier Anastasia Potapova retired trailing 0-5 in the first set.

Gauff, a 17-year-old American, defeated Anastasija Sevastova in the first round. She won the title in Parma and advanced to the quarters at Roland Garros and the fourth round at Wimbledon.

Gauff gains first win over Sevastova at 4th try: Montreal Highlights

Head-to-head: 1-0, Gauff (2020 Roland Garros first round, 6-3, 6-3).

Danielle Collins vs. Jessica Pegula
 
Another unseeded matchup.
 
No.6 seed Simona Halep hadn’t played in three months, following a calf injury in Rome. Collins, meanwhile, had won 11 straight matches – with titles in Palermo and San Jose. Momentum was the critical factor Wednesday, as Collins came back to win 2-6, 6-4, 6-4. She converted her fifth match point for her 12th consecutive victory, but appeared to pick up a leg injury late in the match.
 
Pegula, a 27-year-old American is having a terrific season. She’s 29-14 after a 1-6, 6-3, 6-2 win over the No.10-seeded Anastasia Pavlyuchenkova.
 
Head-to-head: 2-0, Pegula (2012 Midland, 2016 Charlottesville).
 
No.2 Bianca Andreescu vs. No.13 Ons Jabeur
 
Andreescu had to work hard to get past qualifier Harriet Dart on Wednesday, 6-1, 3-6, 6-3. It was a big win for the 21-year-old Canadian who is looking to defend 2,900 points over the next five weeks from her 2019 titles in Toronto and the US Open.
 
She could fall out of the Top 20, if she doesn’t, which is a lot of stress to bear.
 
“I’m trying not to look at it like that because when I do, it’s putting more pressure on me,” Andreescu said. “I try to have a different mindset where I’m going into the tournament, like, `Yeah, I won that tournament before in the past and I’m trying to win it again.’
 
“Just that little switch really helps me. That’s the part that motivates me.”
 
Jabeur had to fight well past midnight to book her spot in the Round of 16, coming back from a set and a break down to defeat San Jose finalist Daria Kasatkina, 2-6, 6-3, 6-4. Jabeur was buoyed by a boisterous Tunisian crowd, who turned Centre Court into a soccer stadium with their cheers and chants.

Jabeur's win sets up not only an enticing meeting first-time clash between two of the craftiest players on tour, but should her fans show up in similar numbers, Thursday night's showdown with Canada's Andreescu should be one of the most boisterous tennis crowds we've seen this season.

We can't wait.
 
Head-to-head: 0-0.