A creditable podium for Singaporean
Lim scorched the lanes with a stunning 279 to beat Fok (179) and defending champion, Sharon Koh (186) of Malaysia and advance to face Tan and Vanessa in the second match.
Lim beat Vanessa, 216-205 but Tan posted a higher 245 to advance to the title match against top seed, Tang Ya-Chun. Both matched stride for stride with strikes and Tang struck out in her final frame to take the match and the title, 278-268.
Teo Li Ying, who was sixth in the first block, missed the stepladder finals by 4 pins to finish in seventh position while Gina Lim, who was third overnight, dropped off to eighth.
Second seed and defending champion, Wu Siu Hong of Hong Kong beat compatriot, Joshua Chow and Chang, 226-199-171 in the second match to face top seed Chang Te-Ming of Chinese Taipei. Wu took the first game, 277-224 but used all his strikes and could not repeat the form to go down 193-234 in the decider and failed to defend his title.
Ng Chiew Pang improved his overnight position from 17th to 11th position with a better second block performance while Justin Lim Chun Liang also moved up from 27th to 15th position.
Detailed scores: Ladies' Open Stepladder | Men's Open Stepladder | Ladies' Open Block 2 | Men's Open Block 2.