American Jack Sock knocked former champion Marin Cilic out of the US Open on Friday in a power-packed 6-4 6-3 6-3 third-round victory at Flushing Meadows.
Sock, who battled back from a two-set deficit to beat the Croat in a Davis Cup duel in July, was impeccable on serve as he did not face a single break point while converting four of six break opportunities against the seventh-seeded Cilic.
"My first time in the fourth round here," Sock said in an on-court interview after dismissing the 2014 tournament winner. "It was a big match for me, a big goal of mine."
With the triumph, the 26th-seeded Sock matched his previous best grand-slam run, having reached the fourth round at last year's French Open.
His opponent in the last 16 will be ninth-seeded Frenchman Jo-Wilfried Tsonga, a straight sets winner against South African 23rd seed Kevin Anderson.
"There's nothing better than playing in front of the home crowd here in New York," Sock said. "I put it out there on the line on every point."