Two of the most intriguing first-round matchups in the Omnium Banque Nationale draw kicked off Tuesday's play, with former finalist Sloane Stephens coming from 2-4 down in the third set to defeat Dayana Yastremska 6-4, 1-6, 6-4, and No.15 seed Coco Gauff gaining her first win over Anastasija Sevastova 6-1, 6-4.

World No.62 Stephens was the victor in a match of stylistic contrasts that saw momentum shift back and forth throughout. Opting for a conservative strategy in the face of Yastremska's flamboyant striking, the American tallied just seven winners to her opponent's 27, but kept her unforced error tally lower with 22 compared to 38.

It was the first encounter between the pair, and as they probed each other's games in the first set neither took real control. Yastremska took an early break lead, but was stymied by a 48% first serve percentage and an error-strewn service game at 4-4. Stephens delivered solid defence, but also picked key moments to unleash on her forehand, with which she found winners to break for 3-2 and to seal her first set point.

Improved serving saw Yastremska land 60% of her first deliveries in the second set, and consequently begin to dominate. The Ukrainian World No.50, playing her fourth event since last November, was in firm control as she sped through a 6-1 second set and raced to a 4-2 lead in the third.

This was as much due to Yastremska's returning as serving: time and again, the 21-year-old fired deep returns at her opponent's feet, exploiting Stephens' footwork and eliciting repeated shanks.

It took real grit for Stephens, runner-up to Simona Halep here in 2018, to turn the match around. She faced four points to fall behind a 2-5 double break in the decider, but fended them off due to a combination of clutch serving and Yastremska's forehand going awry.

But having ground out that hold to pull back to 3-4, Stephens cruised to the finishing line, winning 15 of the last 19 points as Yastremska continued to struggle to find the court with her forehand. Next up for former World No.3 Stephens will be another popcorn clash against a big hitter, No.1 seed Aryna Sabalenka.

Gauff works out Sevastova at fourth attempt

Gauff has had a suboptimal past month, having had to withdraw from the Tokyo Olympic Games due to testing positive for Covid-19.

"The timing of it was terrible," she said. "The actual experience wasn't too bad. I didn't have symptoms other than loss of smell. My dad and my brother had it at the same time as me so I didn't have to quarantine alone. They also didn't have much symptoms. We were one of the lucky ones. I know unfortunately other people weren't as lucky. I'm super grateful that I was able to come out of it unharmed and unscarred."

On her return, the World No.24 faced something of a nemesis opponent. Sevastova had won all three of their previous encounters - each in wildly fluctuating three-set battles, usually the territory on which Gauff excels.

At the US Open last year, Sevastova had won 6-3, 5-7, 6-4 despite failing to close out a 5-3 second-set lead. In Miami this March, she came from a break down in both second and third sets to win 1-6, 6-2, 6-3. Two months later in Eastbourne, she overturned a 4-6, 2-5 deficit to triumph 4-6, 7-5, 6-2.

Here, the Latvian was coming off consecutive opening-round losses at the Tokyo Olympic Games to Fiona Ferro and in San Jose to Petra Martic. She got off to a nightmare start, unable to find either intensity or accuracy for much of a first set in which she committed 13 unforced errors to only three winners.

Sevastova, 31, belatedly began to click only when facing set point at 0-5. A series of touch shot winners were a reminder of her capabilities, but they came too late to prevent Gauff from serving out the set a game later.

The 17-year-old American delivered her first sloppy service game of the match at the start of the second set, and found herself down 0-3. But thereafter, Gauff played her best tennis of the day to win six of the last seven games. With Sevastova's level having gone up, Gauff adjusted well to deal with the plethora of spins and trickery that came her way.

In particular, a handful of judicious net forays won key game points for Gauff, and a fine dropshot sealed the crucial break for 5-4. At the match's dénouement, the net cord played a star role: Sevastova saved one match point as her pass bounced off the net and over Gauff's racquet, but facing a second a forehand dribbled along the net before falling back on her side.

"Sevastova obviously gave me problems in previous matches," said Gauff afterwards. "Even today she's still a tough opponent. Today I just came out on top. She can mix up the game really well, which is what you don't see often on the women's tour. It's definitely troublesome. But what I adjusted today was just focusing more on myself and not about what she does on her side of the court. I think in the past I overthink what she can do. Sometimes it's just better to make your opponent play the ball."

Gauff will next face qualifier Anastasia Potapova in a rematch of their stellar 2019 US Open first round, won by Gauff 3-6, 6-2, 6-4.

Giorgi upsets Mertens; Konta, Pegula progress to second round

Olympic Games quarterfinalist Camila Giorgi continued her scintillating Tokyo form with a 6-3, 7-5 upset of No.9 seed Elise Mertens.

The Italian had not won a set from Mertens in two previous encounters, but was supreme on serve as she captured her third Top 20 win of the year. Giorgi's five aces and 69% of first serve points won were impressive enough, but the World No.71 was also clutch in key moments.

At 1-1 in the first set, she faced triple break point to fall behind early, but managed to get herself out of trouble and instead capture the key break of Mertens' serve in the very next game.

In the second set, Giorgi came through a titanic six-deuce hold, saving four break points, to level at 4-4. Mertens, who was beset by seven double faults in total, committed one to lose serve in the subsequent game - and, after Giorgi had failed to serve out the match, another to fall behind 5-6. This time, Giorgi made no mistake, sealing victory with a rocket backhand winner down the line.

- Insights from
johanna konta
More Head to Head
16.7% Win 1
- Matches Played
83.3% Win 5
elina svitolina

Johanna Konta has arguably even more luckless with Covid-19 than Gauff recently. The Briton was on a high during the grass season, having won her first title in four years in Nottingham - but was forced out of Wimbledon after being designated a close contact of a positive case, and then out of the Tokyo Olympic Games after testing positive herself.

But Konta's return to action saw her face Zhang Shuai, whom she had not only beaten in the Nottingham final but in five straight previous matches stretching back to 2013. Here, Zhang was also hindered by a left leg injury that forced her to retire as Konta led 4-6, 5-2.

Konta, a quarterfinalist here in 2016, will next face No.3 seed Elina Svitolina.

Also moving on was Australian Open quarterfinalist Jessica Pegula, who came from a set down to defeat Anett Kontaveit 5-7, 6-3, 6-3 in one hour and 57 minutes.

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