Veteran Mary Kom (51kg), on the other hand, lost her semi-final bout and thus won her first bronze and eighth medal overall at the World Championships. Jamuna Boro (54kg) and Lovlina Borgohain (69kg) also won bronze after losing their respective semi-final bouts.
Out of the four medallists, two -- Rani and Jamuna -- were making their debut at the World Championships this year.
Rani kept her distance from her Thai opponent Chuthamat Raksat, relying on her jab and countering with combinations for most of the bout. She ended up winning the bout 4-1.
Jamuna, on the other hand, was outplayed by Chinese Taipei's Huang Hsiao Wen in her semi-final. She was the shorter boxer and was moving forward in a bid to get inside Wen's reach and land shots. The strategy didn't work and Wen ended up taking the bout with a unanimous 5-0 decision.
Lovlina's bout against China's Yang Liu was a much closer affair. Liu had a longer reach than her 22-year-old opponent and made it count with her jabs. Lovlina also countered well but the force with which Liu landed her punches gave her the upper hand. She won the bout 3-2.
Mary lost 1-4 to Turkish second seed and European Championships and European Games gold medallist Busenaz Cakiroglu. The Indian camp sought a review of the decision but it was turned down as the International Boxing Association's (AIBA) rules mandate that the decision has to be either 3-1 or 3-2 for the decision to be reviewed.
A protest was also raised during the first round of Lovlina's bout but the technical observer turned down the protest citing consistency of scores with the judges.
Manju will be up against Russian second seed Ekaterina Paltceva in the summit clash on Sunday.