Steve Darcis will face top seed Alexander Zverev in the second round of the Shenzhen Open after edging past Zhang Ze 7-5 7-6 (7-3) on Monday.
Darcis was in action for the first time since helping Belgium secure a place in the Davis Cup final this month and needed an hour and 53 minutes to get past Zhang.
He can now expect to face a significantly more difficult challenge from world number four Zverev, who was part of the triumphant Team Europe at the inaugural Laver Cup on Sunday.
Dudi Sela bagelled Matthew Ebden before coming out on top in a tense tie-break to clinch a 6-0 7-6 (10-8) victory and progress to a meeting with third seed Mischa Zverev, while Jeremy Chardy overcame Alessandro Giannessi 7-6 (8-6) 6-4.
Yuichi Sugita only needed one set to progress to the second round of the Chengdu Open, the fifth seed granted an early passage as Mate Pavic retired after losing the first set 6-1.
Sugita will take on Thiago Monteiro after he came from behind to beat Wu Yibing. There were also victories on Monday for American prospects Jared Donaldson and Taylor Fritz.