Nick Kyrgios was involved in a heated altercation with the umpire over a time violation before composing himself to down world number six Stefanos Tsitsipas 5-7 6-2 6-4 and advance to the quarter-finals of the ATP 500 Halle Open on Wednesday. The volatile Australian was given a warning for taking too long to return Tsitsipas's serve while leading 2-0 in the second set and then proceeded to summon the supervisor to express his displeasure. "He said I was playing too slow - statistically