The Japanese No10 seed eventually triumphed 3-6 6-3 4-6 7-6(7) 6-4 on Monday after play was suspended on Saturday, as he made it to the last 16 at SW19 for the first time.
Nishikori, 24, will face Canadian eighth seed Milos Raonic for a place in the quarter-finals at the All England Club.
“I think it’s good, winning three matches,” said Nishikori. “But this one was a very, very tight match for especially me because he was playing really aggressive and flat.
“He was hitting a lot of winners, and sometimes I didn’t know what to do. I was kind of like a yo‑yo, running from side to side.”
He continued: “I’m very happy. It’s not easy right now to think about the next one.
“There was a lot of stress these two days, especially yesterday. I never had something like this, after playing the fifth set, taking one day off, and playing again today.
“It wasn’t easy. But I’m very happy to win today. So hopefully I’ll play another good one tomorrow.”
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