South Korean tennis player Chung Hyeon has reached his sixth straight quarterfinals on the ATP Tour, a performance that will likely take him inside the top 20 in the next world rankings.

The world No. 23 defeated the 80th-ranked Joao Souza 6-4, 6-3 at the Miami Open on Tuesday (local time), and has now reached the final eight in his sixth consecutive tournament, dating back to the ASB Classic in Auckland, New Zealand, in January. The streak also includes a shocking run to the semifinals at the Australian Open, the season's first Grand Slam event.

Chung has secured 180 ranking points with his latest win. If Nick Kyrgios (No. 20), Milos Raonic (No. 25) and Borna Coric (No. 36) all don't make the semifinals in Miami, Chung could crack top 20 for the first time.

Chung, 21, is already the highest-ranked South Korean tennis player ever, male or female. Chung was 58th in the world on Jan. 1 this year.

He will take on the 17th-ranked John Isner in the quarterfinals. Isner took down the third-ranked Marin Cilic in the round of 16, and has two wins and a loss all-time against Chung.

But in their most recent meeting at the ASB Classic, Chung prevailed over the towering, 208-centimeter American 7-6 (3), 5-7, 6-3.

In Tuesday's match, Chung and Souza were deadlocked at 3-3 in the opening set, before the South Korean broke his opponent's serve and took at 5-3 lead. He eventually took the set 6-4.

Chung broke Souza to open the second set and went up 2-0 en route to a straight-set victory. Chung wasn't broken once in this match.

The Miami Open is a Masters 1000 tournament. The Masters 1000 series is the third-highest tier of ATP tournaments after the four Grand Slam events and the season-ending ATP Finals. Players earn more ranking points at these events than the 500 series and the 250 series tournaments.

Chung had also reached the quarters at the previous Masters 1000 tournament, the BNP Paribas Open in Indian Wells, California, two weeks ago. (Yonhap)