Denis Viktorovich Shapovalov is a Canadian professional tennis player. He has been ranked as high as world No. 10 in singles by the ATP, achieved on 21 September 2020 and a doubles ranking of No. 44, achieved on 24 February 2020. From Wikipedia
The American tennis player called for disciplinary action against chair umpire Greg Allensworth, accusing him of mishandling a heckling incident during a pivotal moment in the match.
