NEW YORK, NY, USA - In a compelling first-round stylistic contrast at the US Open, No.32 seed Dayana Yastremska displayed impressive maturity to escape the spiderweb of Monica Niculescu 6-4, 1-6, 6-2 in one hour and 55 minutes.

The first meeting between the pair was one of the most eagerly anticipated of the opening round: the phenomenal power and all-out aggression of the Ukrainian teenager going up against the wiles and craft of Niculescu promised to be a compelling spectacle. It did not disappoint, although strategically it turned out to be less of a contest between polar opposites than many might have imagined.

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Instead, faced with the array of spins and angles that have ensnared so many youngsters - and not-so-youngsters - over the course of Niculescu's legendary career, Yastremska proved herself able to adapt far beyond the first-strike tennis she usually favours. The 19-year-old was patient and restrained as she embraced the challenge of extended rallies, and countered the Romanian veteran's variety with diversity of her own: dropshots, net forays and even a number of rallies in which she out-sliced the World No.105.
Yastremska quickly shook off a second set in which she had reverted to over-pressing to rein her power in for the decider, and more often than not it was Niculescu - who had not competed since Wimbledon, and whose rust was evident - who lapsed into error first.

Whitney Osuigwe and Elina Svitolina (Getty)

Afterwards, Yastremska revealed that she had practised with Spanish players who shared a similar style to Niculescu so that she could get used to the "little bit unpredictable game" - a style she doesn't necessarily enjoy. "I don't really like this kind of player, but I have to pass them, I have to play them," she laughed. "That was the first time I'd played with a player whose forehand was only slices, so it was a little bit complicated - but I got used to it. I tried to stay with my game, I tried to vary it."

Yastremska's own variety was not just a one-off tactic, though. "It's not just against her - I wanted to change something, to try something new - and we'll see about the future," she said.

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The win keeps Yastremska on a collision course with compatriot and No.5 seed Elina Svitolina in the third round. The WTA Finals champion dispatched 17-year-old wildcard Whitney Osuigwe 6-1, 7-5 in a match of two halves. A nervous Osuigwe failed to do herself justice in a first set in which she seemed to have no answer to Svitolina's all-court tactics, hitting 15 unforced errors to concede it in only 24 minutes. But the 2017 Roland Garros junior champion acquitted herself much better in the second set, impressing with her neat technique and smooth aggression and twice going up a break on the Wimbledon semifinalist.

Eight double faults did not help Osuigwe's cause, though, particularly when serving for the set against a Svitolina who, now alert to her opponent's talent, had locked down her game and raised her level. Asserting her authority with changes of direction and smart point construction, the Ukrainian reeled off the final three games, winning a pulsating baseline rally from corner to corner for one of the finest match points of the day.

Ons Jabeur (Jimmie48/WTA)

Elsewhere, Ons Jabeur caused a minor upset in eliminating No.27 seed Caroline Garcia 7-6(8), 6-2. The Tunisian walked a tightrope of highlights-reel  winners and over-ambitious shot selection in a narrow first set: three times she went up a break, serving for the set twice, and three times let her lead slip. But throughout the ebbs and flows of the match, Jabeur demonstrated superior variety and, when it came down to the biggest points, a cooler head.

The Eastbourne semifinalist was forced to save two set points before finally sealing her fourth with an ace, but ultimately ran away with the second set and finished with an impressive stat sheet of 31 winners, nine aces and a 100% conversion rate of six break points from six.

Meanwhile, Samantha Stosur became the first of the eight former US Open champions in this year's main draw to fall, losing 6-1, 6-3 to the in-form Ekaterina Alexandrova - who had also defeated the Australian at Roland Garros this year - in one hour and three minutes. But No.12 seed Anastasija Sevastova's successful New York history continued apace: last year's semifinalist has reached at least the last eight for the past three years here, and was always in control during a 6-3, 6-3 defeat of Eugenie Bouchard.

No.29 seed Hsieh Su-Wei thrilled Court 9 with a 6-4, 5-7, 6-3 defeat of former World No.50 Jana Cepelova, while 21-year-old qualifier Mariam Bolkvadze made it a Grand Slam debut to remember after upsetting Bernarda Pera 6-3, 5-7, 6-3 in a two-hour, 26-minute epic. Bolkvadze's first ever Top 100 victory was also the first Grand Slam victory for a Georgian woman since Anna Tatishvili reached the fourth round here in 2012. 

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Taking a less scenic route was fast-rising 18-year-old Iga Swiatek, who cracked the Top 50 for the first time during this year's US Open series, and who posted the day's quickest win 6-0, 6-1 over Serbia's Ivana Jorovic to set up a second-round tie against Sevastova. Swiatek beat No.30 seed Maria Sakkari to the finish line by six minutes: the Greek player routed Bronx runner-up Camila Giorgi for the second time in three weeks, bettering her 6-3, 6-0 scoreline in Cincinnati by two games for a 6-1, 6-0 win today.