India's Mary Kom has produced a battling display to overcome Poland's Karolina Michalczuk by five points.
The first round was fought at a relentless pace as Michalczuk bounded forward, while Kom threw shots off the back foot.
The Pole did not allow her opponent to rest for a second as she pursued her around the ring, proving to be a constant menace.
Kom was landing effectively but it did not seem to deter Michalczuk, who walked through most of the shots.
The Indian led by one-point at the halfway stage. She held Michalczuk off with some great left hands to extend her lead to 15-10.
A brusing bout came to a close with the judges awarding Kom a 19-14 win.