West Indies import Danza Hyatt smashed a brilliant century to guide Darley into the Ballarat Cricket Association Twenty20 grand final.
Hyatt made an unbeaten 107 at the Eastern Oval to help the Lions post a score of 5-163.
His side then held East Ballarat to 5-138 in the run chase.
Darley's success sets up a division one final against Mt Clear which defeated Golden Point on Thursday night.
In division two semi-finals on Friday, Dunnstown beat Coronet City and Ballarat-Redan beat Ballan.
Darley will take on Mt Clear in the decider on February 28 with Dunnstown and Ballarat-Redan to go head to head on February 7.