ZHUHAI, China - No.10 seed Dayana Yastremska made a thunderous debut at the Hengqin Life WTA Elite Trophy Zhuhai, saving two set points in the first set to squeeze through a superb contest of brutal hitting that ended No.8 seed Donna Vekic's involvement in the tournament 7-6(6), 6-2 in one hour and 35 minutes.

The Ukrainian's first career Top 50 win had come over Vekic back in 2017 in the semifinals of the St Petersburg ITF 100K event, albeit via retirement - but today, with both ensconced in the Top 25 in the world after breakthrough seasons, put on a breathtaking display to capture their first completed match. For Vekic, though, there will be déjà vu to her disappointment today: for the second round-robin match in as many days, the Croat played an excellent first set only to find herself edged out in a close tiebreak - and, having already fallen 7-6(5), 6-2 to Kiki Bertens yesterday in an almost identical scoreline, is now unable to progress out of the Azalea Group this week.

Having not expected to qualify for Zhuhai after losing to Kirsten Flipkens in the second round of Moscow last week, Yastremska had gone into off-season mode at home in Ukraine: "I didn't practice for five days and I completely relaxed," she explained. But despite her last-minute call-up, this turned out to pay off. "I just don't put pressure on myself," said the 19-year-old. "I realized that I didn't prepare so good, so I just accepted it and I played how I played."

With 39 winners rocketing from her racquet, how Yastremska played was stunning - although, according to her, she had in fact been trying to dial back her aggression. "I was able to play my game, but still to stay a little bit more during the point - you know, to be more patient instead of boom, boom, boom, boom," she claimed.

Indeed, in a serve-dominated opening set that saw only three break points come - and swiftly go - over the course of 12 consecutive holds, Yastremska's boom-boom-boom style was on song from the outset. The phenomenal firepower was relentless from her side of the court, particularly from a forehand wing that drew frequent gasps, such was its raw pace and accuracy.

The youngest player in the tournament also impressed with her boldness on big points and ability to adapt. With Vekic trying to direct as much traffic as possible to Yastremska's slightly less venomous backhand side, the youngster responded by upping the pace with that stroke too, redirecting a number of winners as if to warn Vekic off the tactic.

Over the course of a season in which she has risen from World No.89 to her current World No.24, Yastremska's addition of net play to her game has been a marked improvement, and the Hua Hin and Strasbourg champion showcased that brilliantly on big points. A high backhand volley saved one of only two break points she faced in the eighth game, and the business end of the set saw her pull off several bold drive volleys successfully.

Vekic's role in the overall quality of the match must not be underestimated: for the majority of the set, the 23-year-old calmly withstood Yastremska's power, counterpunching well when necessary but also unafraid to give her opponent a taste of her own forehand weaponry. Three consecutive service winners extricated Vekic from the fourth game, the only one in which she faced a break point, and as she built a 6-4 lead in the tiebreak it was her own strokes that seemed more solid.

With her back to the wall, though, Yastremska peaked. Four jaw-dropping points in which she blitzed returns and one-two punches harder than ever stole the set from under Vekic's nose - and set the stage for the Wuhan quarterfinalist to pull away in the second set.

Though the US Open quarterfinalist rebounded well to win the first eight points on her serve, Yastremska's confidence was now sky-high - as evidenced by the successful introduction of dinked putaways and dropshots into her game to complement her still-rampant power - and an off forehand strike would garner the first break of the set for 3-2.

Vekic would continue to put up valiant resistance, but in vain. Two tightly contested games in a row would both go the remarkably clutch Yastremska's way: strong serving saved a break-back point en route to a 4-2 hold, and Vekic's last stand would be ended by a ferocious backhand return winner on Yastremska's third break point for a 5-2 lead.

Shaking off Vekic desperately unleashing on return, the debutante sent down her fourth ace of the day and three more service winners to set up a decisive final round-robin match against No.1 seed Bertens to determine the semifinalist from the Azalea Group later this week. "She's a good player - a bit uncomfortable for me," mused Yastremska, who lost to the Dutchwoman three weeks ago in the second round of Beijing. "But it's OK, I'm just going to go and play - I don't have another option."