The Frenchman, a winner of the men's singles title at the 2016 European Table Tennis Championships, suffered a 11-8, 11-9, 8-11, 12-10 defeat to Monteiro as the Lusail Sports Arena witnessed a series of surprise results.

Monteiro's success added to a fine day for Portugal as Tiago Apolonia and Joao Geraldo also advanced to the round of 32.

Apolonia beat Japan’s Yukiya Uda 11-13, 11-6, 11-6, 11-6, with Geraldo seeing off Iran’s Noshad Alamiyan 11-6, 11-9, 11-9.

After coming through qualifying, Germany’s Ricardo Walther extended his superb run in Doha with a first-round 11-7, 11-6, 13-15, 9-11, 11-7 triumph against Chinese Taipei’s Chen Chien.

Japan’s Kazuhiro Yoshimura dashed Senegal’s Ibrahima Diaw’s hopes of a place in the next round after claiming a battling 11-7, 9-11, 11-5, 11-13, 11-3 success.

In the women’s draw, South Korea’s 17-year-old star Shin Yubin - who reached the quarter-finals on her last appearance in Doha - saw off Luxembourg’s Sarah De Nutte 8-11, 11-7, 11-5, 11-4.

Yubin will next face Japanese defender Hitomi Sato in the round of 32.

Hong Kong’s Ng Wing Nam came from behind to beat France’s Pauline Chasselin 11-9, 5-11, 7-11, 11-8, 11-8 in a five-game thriller, while Iran’s Neda Shahsavari produced an impressive display to down Ukraine’s Solomiya Brateyko 11-9, 4-11, 11-6, 9-11, 11-7.

Three of the top four seeds fell at the first hurdle in the men’s doubles.

England’s Paul Drinkhall and Liam Pitchford stunned top seeds Chen Chien-An and Chuang Chih-Yuan of Chinese Taipei with a 11-7, 11-1, 5-11, 11-7 victory.

Nima Alamian and Noshad Alamiyan of Iran came unstuck against Hong Kong’s Ng Pak Nam and Lam Siu Hang, losing 6-11, 11-5, 11-9, 11-3.

Third seeds Lim Jonghoon and Lee Sangsu of South Korea also crashed out following a 7-11, 11-8, 11-6, 11-7 defeat by Slovenia’s Darko Jorgic and Belgium’s Cedric Nuytinck.

There was a big casualty in the mixed doubles draw as top seeds Lubomir Pistej and Barbora Balazova of Slovakia let slip a two-game lead to lose 4-11, 9-11, 11-4, 11-7, 11-5 to Chen Chien-An and Chen Szu-Yu of Chinese Taipei.

Second seeds Wong Chun Ting and Doo Hoi Kem will now hope to seize their chance in the competition after defeating India’s Manav Vikash Thakkar and Archana Girish Kamath 11-8, 11-7, 11-8.

South Korea’s Jeon Jihee and Yang Haeun, seeded first in the women’s doubles, powered to a 11-4, 11-4, 11-5 win over fellow compatriots Lee Zion and Choi Hyojoo.

There was disappointment for the second seeds in the competition as Japan’s Saki Shibata and Sato slumped to a 11-6, 11-4, 11-7 defeat to Singapore’s Lin Ye and Zeng Jian.

Competition is scheduled to continue tomorrow.