NEW YORK -- Canada's Milos Raonic has claimed his spot in the fourth round of the U.S. Open.
The fifth seed from Thornhill, Ont., struggled at times Saturday but held off unheralded Victor Estrella Burgos of the Dominican Republic for a 7-6 (5), 7-6 (5), 7-6 (3) victory.
Raonic hammered over 22 aces and 52 winners, breaking on three of 11 chances against the 34-year-old -- the oldest man left in the draw -- in the match that took two hours and 45 minutes.
"It was difficult. He's playing well. He's playing with a lot of aspiration," Raonic said his opponent, who was making his New York debut.
"It was a lot of fun, the atmosphere out there. I'm glad that I was able to play well in the important moments. I had a bit of an understanding what to expect. I played him about four years ago now, so I knew him a little bit."
The 23-year-old Raonic will next face tenth-seeded Kei Nishikori of Japan, who defeated Argentine Leonardo Mayer 6-4, 6-2, 6-3.
The Canadian won the last meeting between the two, in the fourth round at Wimbledon, but lost to the Japanese player in Madrid last spring and Tokyo last fall in the Japan Open final.
Raonic, who reached the Wimbledon semifinals, had to battle both his opponent and a crowd of local Dominicans who gave their player loud and sustained support in the biggest match of his career.
"Victor played really well, this is a very special week for him," said Raonic. "As for me, I've got to keep battling, getting through on grit and trying to find a way to win.
"It's good to get the win," he added. "It's good to put myself in this position in the fourth round to go further in this tournament and give myself an opportunity to play better. I believe I can play better. I believe I will."
Raonic needed to work to win each of the opening two sets against his No. 80 opponent, who finally qualified to play in New York after missing out on five previous occasions.
Seventh-seeded Eugenie Bouchard hopes to join Raonic in the round of 16. The 20-year-old from Westmount, Que., was set to face Czech veteran Barbora Zahlavova Strycova, the 30th seed whom Bouchard has defeated in previous meetings in Osaka last autumn and in Nurnberg on clay this spring.