NEW YORK (Reuters) - John Isner ground out yet another five-set win at the U.S. Open on Sunday, beating Milos Raonic 3-6 6-3 6-4 3-6 6-2 to advance to the quarter-finals of his home Grand Slam for the second time.
The American fired 56 winners and 20 aces to down the former world number three in front of a rowdy, elated crowd inside the refurbished Louis Armstrong Stadium.
Isner endured a five-set bout in the second round and a three-hour 26-minute slog in the third but the eleventh seed showed few signs of fatigue.
"This crowd kept me in it – it was fantastic," Isner said in an on-court interview after another three hours of work against Raonic.
"This is why us tennis players train so hard ... to be in a match like this in front of a crowd like this."
The 6-ft 10-in (208 centimetres) Isner put his powerful serve on display, clocking a 141 mph (227 kph), but said he had finessed other parts of his game.
"There are some matches I've played where I only just rely on my serve. But I think more times than not this year I've shown some other ability," he said.
"That comes from just being relaxed on the court.
"It's not a product of more reps and more practice. The mental part of the game, being able to free up on the tennis court is much easier said than done."
Raonic, who converted only two out of six break points, said Isner, particularly, had been a problem for him.
"I've definitely struggled with him specifically," said the Canadian.
"There are other guys that are big servers that I've played better against. For me, I think the biggest thing is there are not guys that make me hit returns above my shoulders. That's sort of the hardest part for me."
Isner next meets either Croatian Borna Coric or third seed Juan Martin del Potro.
(Reporting by Amy Tennery, editing by Nick Mulvenney / Ian Ransom)
