Ivo Karlovic and Jack Sock are set to square off in an intriguing semifinal matchup on Saturday in Newport. The winner will battle either Rajeev Ram or John-Patrick Smith for the title.

(4) Jack Sock vs. (2) Ivo Karlovic

Karlovic and Sock will be facing each other for the fourth time in their careers and for the fourth time in the United States when they collide in the semifinals of the Hall of Fame Tennis Championships on Friday. The head-to-head series stands at 2-1 in favor of Karlovic, who has defeated the American twice on hard courts; 3-6, 7-6(8), 6-2 at the 2013 Indian Wells Masters and 7-6(4), 6-7(3), 6-3 one season later in Memphis. Sock exacted some revenge shortly thereafter by cruising 6-1, 6-4 on the clay courts of Houston en route to the title.

Grass obviously favors Karlovic, who is looking borderline lethal on the green stuff…