Spanish second seed Rafael Nadal responded to the challenge thrown down by 2014 champion Marin Cilic as he battled to reach the US Open quarter-finals with a four-set win.
Nadal, 33, ultimately had too much quality for the Croatian 22nd seed in a 6-3 3-6 6-1 6-2 victory in New York.
Cilic, 30, briefly rediscovered his best form to level before wilting.
Nadal, the 18-time Grand Slam champion, will play Argentine 20th seed Diego Schwartzman in the last eight.
“For some moments in the second set I felt there were too many points in his hands, he was pushing me back, more aggression than me and he hit every ball very strong,” said Nadal.
“After that second set I thought something needs to change or I would be in his hands. I started to return the second serve inside the court and that created a different perspective.”