New York: Jack Sock sent 2014 champion Marin Cilic crashing out while Madison Keys mounted an epic final set comeback to give the hosts a double US Open celebration on Friday.
Sock, the 26th seed, reached the fourth round for the first time by knocking out a cramping seventh seed Cilic, 6-4, 6-3, 6-3 in tie where he did not face a single break point.
The 23-year-old, whose last two appearances at the US Open had ended in retirements, goes on to face French ninth seed Jo-Wilfried Tsonga.
Sock had defeated Cilic from two sets down in America’s losing effort in the quarter-finals of the Davis Cup.
Tsonga, a two-time quarter-finalist, made the last 16 with a 6-3, 6-4, 7-6 (7/4) victory over South Africa’s Kevin Anderson.
Eighth-seeded Keys won the latest-ever finishing women’s match at the tournament on Monday when she completed victory over compatriot Alison Riske at 1:48am.
On Friday, the 21-year-old was involved in more drama when she rallied from 1-5 down in the final set to defeat Japan’s Naomi Osaka 7-5, 4-6, 7-6 (7/3).
The 18-year-old Osaka was reduced to tears as she twice served for the match but choked under the immense pressure.
“This is the greatest comeback of my career, hands down,” said Keys who will face two-time runner-up Caroline Wozniacki for a quarter-final spot.
Wozniacki, who knocked out ninth-seeded former champion Svetlana Kuznetsova in the second round, clinched a seventh win in seven meetings over unorthodox Monica Niculescu of Romania.
The Dane’s 6-3, 6-1 victory on Arthur Ashe Stadium, which featured eight breaks of serve, was another noise-affected affair.
Angelique Kerber, enjoying a breakout season that has her challenging for world number one, crushed 17-year-old American qualifier CiCi Bellis 6-1 6-1 to reach the fourth round on Friday.
Bellis, the second youngest player in the women’s field, won three qualifying matches and beat two players within the top 65 in the main draw but her dream run ended in a flood of Kerber winners and a rash of errors from the over-hitting teenager.
The second-seeded German took 55 minutes to close out the Day Five program at Flushing Meadows, nearly doubling the 33 points won by Bellis as she notched her WTA Tour-leading 50th match win of the season.
