NEW YORK -- Casper Ruud, the 2022 US Open runner-up, was eliminated Wednesday night when Zhang Zhizhen became the first Chinese man to beat a player in the top five of the ATP rankings.
Zhang upset the No. 5 seed 6-4, 5-7, 6-2, 0-6, 6-2 to reach the third round of a Grand Slam tournament for the second time. It was his second five-set victory to open this tournament after he lost his first four five-setters.
He wasn't discouraged by those previous losses, with the breakthrough finally coming Monday when he outlasted J.J. Wolf in 4½ hours.
"Try to just keep playing and keep believing yourself every single time," Zhang said. "(Even in) tough moments, still try to believe yourself. In the end, you'll make it."
Zhang became the first Chinese man to compete in the main draw at Wimbledon in the professional era when he qualified in 2021. He qualified last year at the US Open, joining Yibing Wu as the first men from their country in the main draw of the year's final Grand Slam tournament.
"Last year at the US Open, I can say it was a bad memory. But this year is a little bit different," said Zhang, who squandered seven match points in his 2022 opener before losing to Tim van Rijthoven in five sets.
The 26-year-old Zhang reached the third round of the French Open in June before falling to Ruud, who had been to the finals in three of the last six Grand Slam events.
"I mean, I'm not sitting here super disappointed with things that I could have done better or my level, but at the most important moments he was the better player. He stepped up," Ruud said. "That was different from Paris. I think in Paris I was the one who really stepped up when I had to. It's a different surface, of course. But he has a great serve, beautiful backhand, and forehand, also. When it's on, it's on and really dangerous."
Ruud, who lost to Carlos Alcaraz last year in Flushing Meadows, is the highest-ranked Norwegian in the history of the ATP rankings, which date to 1973. He had reached No. 2 last year and is currently No. 5.
But after dropping the fourth set in just 23 minutes, Zhang broke Ruud's serve to open the final set, adding a second for a 4-1 lead.
Zhang will face Rinky Hijikata of Australia in the third round, and Ruud believes he can keep on going.
"I was impressed, in a way, how he played," Ruud said. "He's going to be a threat for many years."
With No. 4 seed Holger Rune and Ruud both out, it marks the first time since 2006 that multiple men seeded in the top five lost before the third round of a US Open. In 2006, 3-seed Ivan Ljubičić lost in the first round, while No. 4 David Nalbandian was knocked out in the second.
Ruud, also the runner-up at the French Open in 2022 and 2023, is the first US Open finalist to lose in the first two rounds of the following year's tournament since Kei Nishikori, who lost in the first round in 2015 after finishing runner-up to Marin Cilic in 2014.
ESPN Stats & Information, The Associated Press and Reuters contributed to this report.