The two players had a heated debate at a change of ends during the match won by world number 44 Harrison, with the umpire intervening to calm the situation.
Following his 6-3, 7-6(4) defeat Young took to Twitter to offer his views on what had happened.
"I'm shocked and disappointed, Ryan Harrison, to hear you tell me how you really feel about me as a black tennis player in the middle of our NY match.
"I thought this was supposed to be an inclusive gentleman's sport," the 28-year-old world number 65 said.
Young did not elaborate on what was actually said between the pair, but Harrison was quick to respond.
"The accusations made by Donald Young tonight following our match are absolutely untrue," he said on Twitter.
Source : https://timesofindia.indiatimes.com/sports/tennis/top-stories/american-harrison-denies-wrongdoing-after-young-clash/articleshow/62906958.cms159