Harrison won 7-6 (3), 6-2 over Cristian Garin
in the second round of Delray Beach on Saturday.
Harrison, ranked all the way down at No. 789, earned his fourth win of the week including qualifying as he booked his first-ever quarterfinal spot at tour-level by dropping the top seed. The 26-year-old was just 2-6 in his career at tour-level prior to this week. Harrison will face No. 101-ranked Gianluca Mager
in the quarterfinals, who defeated his brother Ryan Harrison
in the opening round.