Singwancha won the interim title on May 1, 2011, in Phetchaburi against Drian Francisco and was elevated to full champion in November of that year.

He beat Japanese boxers in Japan three consecutive times, facing Daiki Kameda (December 2011), Tomonobu Shimizu (April 2012; eliminator fight), and Nobuo Nashiro (September 2012),[1] he earned a nickname from Japanese journalists "Japan Killer".

At the end of 2012, he was defeated by TKO (referee stopped the contest, judging that Tepparith wasn't in position to continue fighting after being knocked down three times) in the fourth round against Kohei Kono at Ota-City General Gymnasium, Tokyo.

[2] Before starting his boxing career Tepparith trained and competed in Muay Thai under the name Theparith Wor.Singsanae (เทพฤทธิ์ ว.สิงห์เสน่ห์), he had over 200 fights for 160 wins.

After two quick first round KO wins Tepparith faced high level competition in RISE champion Masahiko Suzuki who he fought at RISE World Series 2021 Osaka on July 17, 2021.