Bai, who had beaten Ng in the finals of the UK Championship, Niche Cues Open, and WSF Women’s Championship the previous season, started strong by taking the opening frame.
However, Ng responded by winning a tactical second frame on the black, then added the third with a match-high break of 85 to lead 2-1.
Bai fought back to level the match, but Ng was not to be denied a memorable victory against the world number one.
She produced further breaks of 38 and a composed 66 in the final frame to secure a 4-2 win.
As the tournament’s top two seeds, both Ng and Bai were automatically seeded through to the knockout phase, bypassing the initial group stages.
The 35-year-old Ng defeated Scotland’s Deborah Fladgate and world number six Narucha Phoemphul to reach the semi-finals.
There, she swept past England’s Rebecca Kenna 4-0, firing a tournament-high break of 104 to reach her fifth world ranking event final in six appearances this season.
With this victory, the SAR ace becomes only the fifth player to win the British Open three or more times.
She now has 24 career titles, moving within two of Karen Corr, who currently stands fourth on the all-time list.
The win also marks Ng’s second straight title, following her triumph at the Belgian Open last month.
Edited by Aaron Tam
