The 25-year-old, racing in the seventh pair, clocked 1 minute 14.02 seconds, but was then forced to endure an agonisingly long wait as a further 11 pairs of skaters completed the 2.5 lap course at the Adler Arena.
Ireen Wüst of the Netherlands, who earlier won 3,000m gold, claimed the silver in a time of 1:14.69, while her compatriot Margot Boer (1:14.90) won bronze to continue the Netherlands’ impressive showing in the speed skating events in Sochi.
"Now I am super happy,” said Zhang at the finish. “It's hard to accept the reality that I have won the 1,000m.
“I didn't care what time I went on the ice. I'm competing with myself. I was very nervous as I was waiting and I don't think anybody could have understood how I felt waiting,” she added.
“I won, I won. Tomorrow is my coach's birthday so I want to give him the prize of me winning the 1,000m as a present!”
Change of plans
Zhang admitted that she had not expected to have cause for celebration in Sochi, and had originally planned to head home straight after finishing her event.
"I was planning on going back to China tomorrow but now I think I need to reschedule my ticket,” she revealed.
A number of skaters threatened Zhang's time during their skates but could not sustain the required pace until the finish line.
Russian 1,000m world champion Olga Fatkulina finished just outside the medals, while the much fancied American Heather Richardson, who has won three out of four World Cup races this season, could only finish seventh, 1.21 seconds off the pace.
World record holder Brittany Bowe of the USA took to the ice in the penultimate pair but could make no impression on Zhang’s time, finishing eighth.
Zhang's best World Cup performance this season in the 1,000m has been sixth.
“This was a tough one, but my time in the 1,000m is really good for me,” commented silver medallist Wüst. “I had a good start, but I missed the speed you need in the 1,000m.”
“It was hard in the last few days,” she added. “At the Olympic Games there are four days in between my last race and this one. It's hard to focus.”