Donald Young had never before beaten John Isner in an ATP match. But he also had never had a warmup to Isner. At the Memphis Open presented by ServiceMaster, Young got his warmup as well as his win. Facing 6-foot-11 Reilly Opelka in the 2nd round, Young was able to get a read on the big man’s serve, something he said was key in his 7-6, 3-6, 7-6 win over Isner.

“I’ve never had a warmup to John before, to have that was actually good,” Young said. “To see the trajectory (of the serve) … it was  the round right after. Different serves, different spins but (the angle) from where it was coming from was about the same.”

Young actually won 13 points less than Young in the match, but he captured the most important ones, particularly in the 1st and 3rd set tiebreakers. Young seemed as surprised as anyone that he was able to win both tiebreakers and reverse his history with Isner.

“I won a couple of key points, put my racquet on some serves and took care of my service points which was key,” Young said.

Young’s opponent in the semifinals will be another American, this time Ryan Harrison. Harrison has breathed life into his career of late, climbing back into the Top 65 in the world rankings after being outside the Top 100.

Harrison topped Bosnian Damir Dzumhur 6-3, 6-4 in a more straight-forward affair. The 24-year-old will play Saturday for a spot in his first ATP final.