The 22-year-old overcame the third and final qualifying hurdle by beating German veteran Dustin Brown 6-1, 7-6 (12/10).
“I felt really good throughout the match. The first set went by in a blink of an eye but in the second set, the match had a lot of swings and big moments. Dustin Brown is one of the trickiest opponents, so I had to stay calm and focused throughout,” Harris said.
Harris continues his rise in international tennis following a stellar 2018 reaching a career-high 110th ATP world ranking after winning two Challenger Series titles.
He made it into his first Grand Slam at the 2018 US Open where former world number six Gilles Simon of France knocked him out in the first round.