To compete with him well, I always have to have a great day, and I have to play well.
Thiem, a finalist at this year's French Open, neutralized the 6-foot-8 Anderson's blistering serve by standing far beyond the baseline and he chased down everything the South African could throw at him.
Aug 31, 2018; New York, NY, USA; Denis Shapovalov of Canada reacts against Kevin Anderson of South Africa (not pictured) in the third round on day five of the US Open at USTA Billie Jean King National Tennis Center.
Finally, Basilashvili's strength waned and in the fourth set, the Spaniard broke out into a 4-3 lead to end the match victorious.
Thiem, not Anderson, dominated on serve, winning 91 percent of his first-serve points (41/45) and never facing a break point.
Williams and Kanepi meet in a fourth-round match Sunday, when defending U.S. Open champions and Sloane Stephens also are in action.
Anderson, who lost to Nadal in the 2017 Open final, lost his first set and played under a closed roof for the first time in Louis Armstrong Stadium history.
Anderson won the first six of their head-to-head meetings, all on hard courts.
His appearance in the quarter-finals at the US Open means he has reached at least that stage in all four Grand Slam tournaments this year, for the first time since 2011.
"Against Rafa, I've had three very nice experiences and seven disgusting experiences", said 24-year-old Thiem.
That extra time on the court may prove costly when Nadal is faced with the Austrian, who showed his class to send Kevin Anderson packing, in a clash where a similar performance again would surely be punished.
Six-time women's victor Serena Williams booked her place in the last-eight with a 6-love, 4-6, 6-3 victory against Kaia Kanepi. "To win in straight sets in every round is good for the body and physical condition", said Del Potro popularly referred to as DelPo. "I just hope to keep my level high against John (Isner) in the next match".
A quarter-finalist in NY seven years ago, Isner was asked to compare his game then and now.
Isner, the 11th seed, is the only American man left as he attempts to become the first home victor since Andy Roddick in 2003.
"There were a lots of ups and downs in the match". The day's other last-16 duel sees United States 11th seed John Isner tackle fellow big-server Milos Raonic, the 25th seeded Canadian.
Nono Dzgania, a 57-year-old woman from Georgia who now lives in the Washington Heights neighborhood of Manhattan, watched Makatsaria on Sunday while Basilashvili was in Ashe.
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