First on clay and now on grass, China's pioneering tennis star Zhang Zhizhen has served up further proof of his all-around evolution with a shock victory over world No 5 Daniil Medvedev at the Halle Open in Germany.

An emerging star developed in China's hard-court-dominant system, Zhang demonstrated his growing adaptability — a necessity to achieving success in pro tennis — in remarkable style on Wednesday, by stunning the Russian third seed Medvedev in three sets at the ATP500 tournament. And he did it on grass, a surface very few of China's current professional players had access to in their youth careers.

Undoubtedly the underdog in the face of the former world No 1 and 2021 US Open winner, the currently 42nd-ranked Zhang punched well above his weight. He came back from 3-5 down in the third-set tiebreaker to upset Medvedev 6-3, 2-6,7-6 (5) in two hours and five minutes.

Zhang's second career victory over a top-5 opponent, following a five-set win against Casper Ruud at last year's US Open, helped him advance into his first quarterfinal at Halle, and will almost certainly see him crack the world top 40 for the first time.

After pulling off such a statement win on his least familiar surface, Zhang revealed that it was an unspoken "rivalry" with his old pal that drove him to come back in the tough moments.

"It was a really tough match. Last time (facing Medvedev) I lost a third-set tie-break," Zhang said of his 2-1 loss to Medvedev in their only previous encounter in 2016 — a qualifier for an ATP250 event in Nice, France.

"And today, again, it was a third-set tie-break. I was thinking, 'OK, it's time. The perfect moment to get revenge.' I'm super happy that, today, I hung on in there until the end," said Zhang, who developed a friendship with Medvedev while training together at an academy in Nice about 10 years ago.

"I didn't really think too much on the tiebreak, just tried to play point by point."

Zhang next plays against 44th-ranked Christopher Eubanks of the United States on Friday in the quarters, and, should he keep going, a potential meeting with Italy's reigning world No 1 Jannik Sinner, or Greek star Stefanos Tsitsipas, will await him in the semifinals.

Consistent rise

Since climbing into the world's top 100 for the first time in 2022, Zhang has consistently managed to remain among the elite echelon on the men's pro circuit, a feat never before achieved by any of his countrymen.

His much improved mental game, coupled with his natural physicality, honed by big-time wins at top-flight events, such as the ATP Masters and the Slams, has helped him stay composed and confident, no matter who he faces on the tour.

After making history by becoming the first Chinese man to fight his way into the quarterfinals at the clay-court Madrid Open last year, Zhang, who spent a few years training on clay in Europe in his junior years, backed up his credentials on the surface by repeating his run to the last eight at another Masters tournament in Rome last month.

His second third-round appearance at the French Open recently, where he was stopped by ninth-seed Tsitsipas, also bore witness to the growing mastery of his craft in his versatile handling of seasonal surface shifts.

Grass, however, remains relatively uncharted territory for Zhang, who started the 2024 grass season with a career winning percentage of 28.6 on the surface, his lowest among the three types. However, he quickly earned his first win on grass this season by beating Sebastian Ofner 2-1 in the opening round in Halle to set up his clash with Medvedev.

With the high-profile Wimbledon Championships just around the corner, Zhang's maturing game on grass and, more importantly, his confidence when taking on the sport's top players have all added fuel to fans' expectations for a breakthrough at the All England Club.

"I always like to play on grass. Even though the results haven't been so solid in the last couple of years, I will try to enjoy playing on grass more this season," said Zhang, who has twice played in the main draw at Wimbledon, in 2021 and '23, falling to opening losses on both occasions.

sunxiaochen@chinadaily.com.cn