Japanese teenager Kei Nishikori’s ground-breaking US Open run came to an end in the fourth round on Monday with a 6-3 6-4 6-3 defeat by fellow young gun Juan Martin Del Potro of Argentina.
The 18-year-old, the first Japanese man to reach the last 16 in the U.S. Open since 1937, was outgunned by Del Potro, the 17th seed who extended his winning streak to 23 matches.
“I was a little tired, obviously, and mentally more tired,” Nishikori told reporters.
“At the same time, he was playing really well. He didn’t miss any balls. He was just playing well. I was just waiting (for) his mistake (and) I couldn’t use my forehand.”
Del Potro, 19, will now play sixth seed Andy Murray of Britain.