Fighting in a larger weight class than most Thai fighters, Tengnueng has become a fan favorite in the promotion and is a main event staple.
On November 8, 2014, Tengnueng defeated Kompetchlek Lookprabat to become the 2014 Omnoi Stadium Weber 154 lbs Tournament Champion.
Tengnueng started 2016 with a 2nd-round TKO victory over Daniel Kerr of Germany at THAI FIGHT Korat 2016 on March 19, 2016.
[9] On October 5, 2016, Tengnueng defeated Erik Massion of Germany by 1st-round KO at THAI FIGHT Emei.
[10] He would then go on an uncharacteristic three-fight losing streak, including a decision loss to Hamza Ngoto at THAI FIGHT Paris on April 8, 2017.
His first opponent of the year was Russia's Mike Vetrila, whom he knocked out in the 1st round, keeping his streak of KO wins alive at 12.
Tengnueng seemed to return to his previous form, despite his weight gain, when he delivered a 1st-round KO of Simon Maait of Australia at THAI FIGHT Samui 2019 on April 27, 2019.
[12] However, this was not to last as his performance was called into question when he faced Mohammad Hossein Doroudian of Iran at THAI FIGHT Betong 2019 on June 29, 2019.
[14] Tengnueng was eventually booked for a rematch with Mohammad Hossein Doroudian at THAI FIGHT Bangsaen 2019 on October 26, 2019.
This time around, Tengnueng captured the 1st-round KO victory with a series of high kicks that gradually wore down Doroudian's arms.
While he dominated the entire 3 rounds of the fight, Tengnueng was unable to finish off Delavar and ended up getting the win by decision.
Nevertheless, Tengnueng took the decision victory and was awarded a THAI FIGHT Kard Chuek Superfight 81 kg belt.
Tengnueng is scheduled to rematch Nicolas Mendes in the 72.5 kg Tournament Final, whom he previously fought at THAI FIGHT New Normal the year before.
[18] Due to travel restrictions pertaining to the COVID-19 pandemic, Mendes was later replaced by Thomas Carpenter in the Tournament Final.