Following an 11-7, 11-7, 11-3, 11-5 win over Lithuania's Rimas Lesiv, the 2017 champion went onto beat Portugal's Joao Geraldo 11-4, 11-6, 11-4, 12-10.

Awaiting Yan in round three is France's Emmanuel Lebesson, who received a bye in round one before defeating Italy's Leonardo Mutti 8-11, 11-2, 11-5, 11-8, 11-3.

Another former champion advancing to round three is Austria's Daniel Habesohn, the 2014 winner, with an 11-6, 11-8, 11-3, 6-11, 11-7 victory over Chinese Taipei's Hung Tzu-Hsiang.

Next up for Habesohn is Belgium's Florent Lambiet after his 11-6, 11-3, 11-8, 11-9 win at the expense of Germany's Nils Hohmeier.

There was disappointment, however, for 2015 champion Jiang Tianyi of Hong Kong at the Budapest Olympic Hall. 

He crashed out in the second round after falling to a 7-11, 11-13, 8-11, 8-11 loss at the hands of Spain's Carlos Machado.

Machado’s reward is a meeting with China's Zhao Zihao, who overcame Serbia's Ivor Katic 8-11, 11-5, 11-6, 11-6, 11-3 in round one and Slovenia's Bojan Tokic 11-7, 11-8, 11-4, 10-12, 11-2 in round two. 

In the opening preliminary round of the women's singles event, world number 498 Aneta Maksuti caused the biggest upset by beating Hong Kong's Ng Wing Nam in a tense seven-game encounter.

The Serbian triumphed 11-4, 4-11, 11-5, 3-11, 9-11, 11-7, 11-8 to set up a second-round meeting with Germany's Kristin Lang. 

"I played really well today - my backhand and forehand both were working well," Maksuti said.

"I've surprised her playing a lot down the line as well as being able to hit a lot of winners.

"Most difficult was to read her serve, but once I could see the spin better, I felt really confident.

"That helped me in the final game."

Lang progressed from the first round with an 11-5, 11-8, 4-11, 10-12, 11-5, 12-10 win over Poland's Magdalena Sikorska. 

Action in Budapest is due to continue tomorrow.