The 20-year-old Capetonian this week reached his career high ranking of 199 on the ATP World Tour Rankings after reaching the semi-finals of the Challenger event in Taiwan last week.
READ: Goffin into ATP top 10, Anderson 15th
Harris was the star of the South African Davis Cup team who beat Denmark 3-1 last month promoting South Africa into the Euro/Africa Group 1 of Davis Cup by BNP Paribas.
Harris won both his singles rubbers in the promotional tie played in Aarhus, Denmark.
"I am really happy to have reached my career high of 199," said Harris.
"I have been working hard and playing some good tennis and feel excited about the future and I know there is still a lot of room for improvement in my game. It's great to see the hard work, sacrifices and dedication is slowly but surely paying off."
Harris will play in the ATP Challenger event this week in Tashkent, Uzbekistan and is hoping to qualify for next week's ATP Tour 250 event, The VTB Kremlin Cup in Moscow, Russia.