In 2019, he won the Lingshui China Masters, defeating Liu Haichao in straight games in the final.

There, he defeated Denmark's Victor Svendsen to reach his career's maiden World Tour Super 500 final.

In the final, he defeated Indonesia's Jonatan Christie to win his career's biggest title, despite being one game down and trailing 16–19 in the second.

He defeated former World No.1 Srikanth Kidambi and Olympic bronze medalist Anthony Sinisuka Ginting to enter the semi-finals.

[5] Weng won his second BWF World Tour Super 500 title at the Australian Open, with victories against Kodai Naraoka, Chou Tien-chen and Lee Zii Jia.