With the tightly packed field passing through the 400 metres, many runners started to fall behind and could not handle the pace set by early leaders Sun Yingjie and Xing Huina.
Approaching to the halfway mark of the race, Turkey's world-record holder Elvan Abeylegesse surpassed the Chinese duo to charge into the lead and the pace began to accelerate quickly.
With only three laps to go, Abeylegesse struggled to maintain her pace until she finally faded on the backstretch, leaving Defar and Ochichi to exchange the leading duties throughout the race and battle out for the gold.
Moments after the bell, Ochichi continued to lead from the rest of the field, but Defar patiently passed her with only 200 metres to go, and then stormed away to her first Olympic title, finishing at 14:45.65.
For the women's 5000 metres, each National Olympic Committee was permitted to enter up to three athletes that had run the race in 15:08.70 or faster during the qualification period.