HUA HIN, Thailand - In her first WTA Tour tournament as a seed, Dayana Yastremska is settling comfortably into her new status, progressing to the quarterfinals of the Toyota Thailand Open presented by E@ with a 6-1, 6-4 defeat of wildcard Peng Shuai in one hour and 13 minutes.

It is the No.8 seed's second last-eight showing of 2019 already in addition to Hobart three weeks ago, and marks the fifth consecutive WTA main draw in which Yastremska has won two or more matches. Peng, who captured her first win of the year over qualifier Chloe Paquet in the first round, last made a WTA quarterfinal at Tianjin 2017.

"It was a good match," assessed Yastremska. "At the beginning I felt very comfortable in the court and I was hitting everything very well. In the second set I felt a little bit weak... and I was just trying to keep my emotions under control and be really focused."

In a dominant first-set display, Yastremska's ability to come up with her best tennis on big points trumped her inconsistency. At times, the Ukrainian appeared unplayable, such was the quality of her first-strike shotmaking: particular highlights were the skidding forehand returns that garnered her a break for 0-2, and the forehand winner down the line at full stretch that landed in the corner to save a break point in the fifth game.

Teeing off on every shot is a high-risk strategy, though, and on occasion Yastremska would overpress and consequently find herself embroiled in mini-battles. But every time, the teenager - who cracked the Top 50 for the first time this week after her third-round showing at the Australian Open - would regain control of her power.

Three consecutive games went to deuce in the first set; Yastremska won all of them, while putting together both a 100% break point conversion rate (two out of two) and a 100% record of saved break points (four out of four, including an ace to get herself out of a hole dug by three double faults in the fifth game).

Raising her level on serve, Peng was able to make the second set a closer affair as the first eight games came and went without a break point chance for either player. But the Chinese player was unable to find an answer to Yastremska's first serve - although the Hong Kong champion landed just 40% of them during the match, she would only drop four points in total when that happened.

In the ninth game, it was Peng who blinked first, with three groundstroke errors giving Yastremska the first sniff of an opportunity. The 33-year-old World No.129 battled valiantly as Yastremska continued to oscillate between wild errors and breathtaking winners, but in the end it would be the former junior Wimbledon finalist who broke through on her fifth break point.

Capping off a superb display, Yastremska served the match out to 15, racking up her fourth and fifth aces of the match and finishing with a booming backhand winner, her 28th of the day (balanced against 26 unforced errors). Up next for the youngster is a quarterfinal titl against either No.1 seed Garbiñe Muguruza or Mona Barthel.

"I don't know which one I prefer," Yastremska laughed afterwards, pointing out that she had played both of them after the US Open last year - defeating Muguruza in Luxembourg, but losing to Barthel in the Chicago 150K.