On the September 5 broadcast of MBN's 'Voice Trot', the contestants competed in a fierce fourth round where each of the singers had to directly call out a rival opponent to go up against. 

On this episode, idol contestant UP10TION's Sunyoul boldly called out comedian Son Heon Soo as his opponent. Many of their fellow competitors suspected from the beginning that the comedian's run on 'Voice Trot' was all but finished, based on Sunyoul's excellent scores in the competition so far. 

For his 4th round song, Sunyoul chose a much more slow-tempo, ballad trot version of Hong Jin Young's "Cheer Up". However, before going on stage, it was revealed that due to over-practicing, Sunyoul had contracted a vocal cord infection. It was further revealed that the idol visited the hospital merely hours before the 'Voice Trot' recording in order to receive treatment. However, despite his poor health condition, Sunyoul delivered an emotional stage topped with his signature, elegant high-tone voice. 

Against Sunyoul, comedian Son Heon Soo put on an energetic performance of Seol Woon Do's "Coincidentally". But ultimately, after tallying the votes from the celebrity judges as well as the audience, Sunyoul was chosen as the winner, and the idol will be moving on to 'Voice Trot's semifinal round next week.

Check out some clips of UP10TION's Sunyoul on this week's 'Voice Trot', above and below!