Jack Sock scores his second singles win in 15 months at the Delray Beach Open by VITACOST.com

John Isner and Jack Sock celebrate their doubles win at the Laver Cup.

Nick Kyrgios and Jack Sock spoiled the debut team outing of Rafael Nadal and Stefanos Tsitsipas at Laver Cup.

Jack Sock owns a 6-3 record in Laver Cup matches.

Team World is eager to pull off the upset at the 2019 Laver Cup.

Jackson Withrow and Jack Sock talk tactics during their upset win over 2018 finalists Juan Sebastian Cabal and Robert Farah on Thursday at the Australian Open.

Jack Sock and Mike Bryan celebrate lifting the doubles crown at the Nitto ATP Finals.

Mike Bryan and Jack Sock battle hard on Sunday to work their way back into the doubles final at the Nitto ATP Finals.

Mike Bryan and Jack Sock won their second straight Grand Slam title at the US Open.

Jack Sock and Mike Bryan drop just one set en route to claiming the 2018 US Open title.

Mike Bryan and Jack Sock win their second consecutive Grand Slam championship, triumphing at the US Open.

Mike Bryan and Jack Sock will bid for their second straight Grand Slam doubles title together after holding off Colombians Robert Farah and Juan Sebastian Cabal at the US Open.

Mike Bryan and Jack Sock defeat Maximo Gonzalez and Nicolas Jarry in straight sets at the US Open on Wednesday.

Mike Bryan and Jack Sock defeat Mackenzie McDonald and Yoshihito Nishioka in 59 minutes to reach the US Open third round on Saturday.

Mike Bryan and Jack Sock lift their fourth and second Wimbledon titles, respectively, on Saturday.

Mike Bryan and Jack Sock defeat Raven Klaasen and Michael Venus to capture their first title at The Championships as a pair.

Mike Bryan and Jack Sock defeat Dominic Inglot and Franko Skugor in five sets to reach the final at Wimbledon.

Jack Sock and Mike Bryan advance to the Wimbledon doubles semi-finals on Tuesday.

Jack Sock and Nick Kyrgios defeat Roman Jebavy and Matwe Middelkoop to win the Open Parc Auvergne-Rhône-Alpes Lyon on Saturday.

Nick Kyrgios and Jack Sock move through to their first ATP World Tour doubles final in Geneva on Friday.

Nick Kyrgios and Jack Sock defeat Federico Delbonis and Joao Sousa in straight sets to reach the Open Parc Auvergne-Rhône-Alpes Lyon quarter-finals on Tuesday.

John Isner (left) and Jack Sock fell on Thursday in the Rome second round to fourth seeds Henri Kontinen and John Peers.

Jack Sock pulls off a tweener against Horacio Zeballos on Thursday in Houston.

Jack Sock, the 2015 Fayez Sarofim & Co. U.S. Men's Clay Court Championship winner, is the third seed in Houston this year.

The United States Davis Cup team celebrates reaching its first semi-final in the event since 2012 by eliminating defending finalist Belgium.