- Tag results for Jack Sock
Team World's Jack Sock and Kevin Anderson needed a tiebreaker to defeat the doubles dream team of Federer and Djokovic 6-7, 6-3, 10-6.
The pair won its second straight Grand Slam doubles title together, beating Lukasz Kubot and Marcelo Melo 6-3, 6-1
Jack Sock hadn't won a singles match since a first-round victory over David Ferrer at the Rome Masters in May.
Bryan teamed with US compatriot Jack Sock to beat Raven Klaasen of South Africa and New Zealand's Michael Venus 6-3, 6-7 (7/9), 6-3, 5-7, 7-5 in the Wimbledon final.
From his knees at the middle of the net, Federer struck volley after volley right back at Sock until the American star finally faltered.
Towering 20-year-old Opelka, playing in his first ATP level tournament of 2018, fired 17 aces past world number eight Sock to cap a day of upsets.
The eighth seed tumbled out of the tournament on the end of a 6-1, 7-6, 5-7, 6-3 loss in two-and-a-half hours to the 41st-ranked Sugita.
Jack Sock and CoCo Vandeweghe gave the United States a perfect start to the 30th edition of the mixed team Hopman Cup event by winning their singles matches in the opening tie against Russia.
Jack Sock became the first American to reach the semi-finals of the season-ending event since Andy Roddick in 2007.
Roger Federer made a strong start to his bid to cap his golden year as the Swiss star defeated Jack Sock on Sunday.
The 'next-gen' stars will be hoping to step up and display their skills to fill in the gap at the French Open.