In 2008, he won the final stage of French Open 2008 Boys' Doubles Juniors category with Finnish tennis player Henri Kontinen.

[3] He won his maiden ATP Tour title in men's doubles, partnered with Swedish player André Göransson in February 2020, 13 years since going pro.

[7] A year later at the 2018 Asian Games in his home country, Rungkat was partnered up with Aldila Sutjiadi for the mixed doubles category in just two weeks, and was not targeted to grab any medals.

[9][10] In February, Rungkat reached his first doubles final ATP Tour 250 at the Sofia Open with partner Hsieh Cheng-peng.

They then surprised the French team of Benoît Paire and Antoine Hoang in straight sets, before securing a spot in the final with a win over Romain Arneodo and Andre Begemann 6–4, 7–6(7–1).