The 23-year-old Khushbir took one hour, 40 minutes and 33 seconds to complete the distance. Khushbir's show was far from her national record mark of one hour, 33 minutes and 37 seconds.
The Asian Games 2014 silver medallist completed the first 10km in 47:35 minutes and was in the 48th position. Till then, she was 2:11 minutes behind the leader.
But afterwards, racewalker from Amritsar ran out of gas as the race progressed and finished 54th and was 11:58 minutes behind the winner -- Liu Hong of China, who won the race in 1:28:35.
Sapna failed to finish just after the 8km mark.
The silver medal went to Maria Guadalupe Gonzalez, who finished two seconds behind Hong. Maria became the only second Mexican woman to claim an Olympic medal in athletics, following the silver medal by Ana Guevara in the women's 400m in 2004, reports Xinhua.
"I feel good. I was hoping to get the gold and I raced as hard as I could and gave it everything. But I am happy. Next time I will have to race harder," she said.
Lu Xiuzhi took the bronze medal with a timing of 1:28:42.
Hong and Xiuzhi had finished fourth and sixth in the 2012 London Games.
The 29-year-old Hong said: "It was hard because the weather wasn't that good. The only thing I could do was keep going, do my best and try to make it perfect.
"It means a lot to me. I have been doing this sport for more than 10 years now," Liu added. "This time I was doing my best to get a medal and I am pleased I could get the gold."
Italy's Antonella Palmisano was fourth and China's Qieyang Shijie fifth.
