Alexander Zverev will face Dominic Thiem in the quarter-finals of the 2018 French Open after the pair beat respective fourth-round opponents Karen Khachanov and Kei Nishikori on Sunday.
Zverev is through to his first major quarter-final after besting Khachanov, although some might still question the German's title credentials after grunting to his third successive five-sets victory at Roland-Garros.
Thiem faced a higher-profile opponent in No. 19 seed Nishikori but managed to make it past the Japanese star, losing just one set and looking largely good value as he won 6-2, 6-0, 5-7, 6-4.
Mihaela Buzarnescu couldn't maintain the momentum gained from her third-round surprise win over Elina Svitolina and fell to American Madison Keys 6-1, 6-4 on Sunday.
Novak Djokovic will be in action later on Sunday and faces Fernando Verdasco, while women's second seed Caroline Wozniacki will attempt to continue her fine run of form against Daria Kasatkina.
(2) Alexander Zverev bt. Karen Khachanov: 4-6, 7-6 (4), 2-6, 6-3, 6-3
(7) Dominic Thiem bt. (19) Kei Nishikori: 6-2, 6-0, 5-7, 6-4
(8) David Goffin vs. Marco Cecchinato
(20) Novak Djokovic vs. (30) Fernando Verdasco
(13) Madison Keys bt. (31) Mihaela Buzarnescu: 6-1, 6-4
(26) Barbora Strycova vs. Yulia Putintseva: 6-4, 6-3
(10) Sloane Stephens bt. (25) Anett Kontaveit: 6-2, 6-0
(2) Caroline Wozniacki vs. (14) Daria Kasatkina
Visit the Roland-Garros website for the results in full.
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Not only was this Zverev's third five-set face-off in succession, but Sunday's victory over Khachanov was also the third time in a row he's responded after falling behind two sets to one.
Khachanov looked the more likely winner as he led after three sets too. The Russian pieced together a streak of five consecutive games to put himself within touching distance of the quarters, and it was at this point the New York Times' Ben Rothenberg cast his judgment on Zverev's display:
Stamina is certain to play more of a role in Zverev's tournament as he progresses, and the concern is that while he's played 15 sets of a possible 15 since the second round, No. 1 seed Rafael Nadal has yet to drop a single one.
But the 21-year-old endured and appeared to benefit from a moment of clarity between the third and fourth set. Zverev dropped serve five times in the opening three sets but failed to do so in the final two, and tennis writer Tumaini Carayol expressed a much more positive belief in his talents:
Promising though his comeback might have been, however, Thiem is the highest-quality opponent he will have faced in Paris. The Austrian forced five breaks upon Nishikori in the opening two sets of their clash and survived a comeback attempt to advance, earning high praise from Jose Morgado of Record:
José Morgado @josemorgado
Dominic Thiem, who had never won a set against Kei Nishikori before today's match, playing a flawless match so far. Kei a step (or two) slower, missing a lot and looking super flat, but Dominic doing all right, one of the best matches I've seen him play in 2018. 6-2, 6-0 https://t.co/cOwiptHUVZ
Thiem, 24, has dropped one set in each of his 2018 French Open outings and will come up against another player seen as an emerging force of tennis' next generation of superstars.
On the women's side of things, Keys may well be counted among that number too and indicated why she's so revered as a developing talent, beating Buzarnescu in straight sets and capping off the match with a powerful ace:
This is Keys' first time travelling to the quarter-finals at Roland-Garros and means she's now made the final eight of all four Grand Slams.
Keys has yet to drop a set at the 2018 French Open and will come up against either Barbora Strycova or Yulia Putintseva in the next round, with that pair scheduled to clash later on Sunday.