What Gabriel Diallo is doing in the US Open right now hasn’t been done by a former Kentucky Wildcat since 2009. On Thursday in New York, Diallo took down No. 24 Arthur Fils in the second round of the US Open, winning in four sets (7-5, 6-7 [3], 6-4, 6-4) and thus advancing to the third round on Saturday where he’ll take on No. 14 Tommy Paul of the USA. Diallo, who was a multi-time All-American during his time in Lexington (2019-22), has now won five straight matches on the courts of the USTA Billie Jean King National Tennis Center after entering the main draw as a qualifier. The Canadian picke…