Zhang was given plenty of problems by the veteran Belarus athlete Vladimir Samsonov and looked in trouble when he fell 3-2 behind.
But the world champion showed real guts in moving through the gears to claim the next two and set up a quarter-final clash with Hong Kong's Jiang Tianyi.
'I was prepared for a very tough match,' admitted Zhang. 'But I do not think there is anything to improve on; if I carry on playing like this I will win.'
I was prepared for a very tough match. But I do not think there is anything to improve on; if I carry on playing like this I will win.Zhang Jike
In a quite incredible display, Michael Maze dominated every game against his Japanese opponent and eventually won 4-0.
That set up an all-European last-eight encounter with German Dimitrij Ovtcharov, who cruised to a 4-0 triumph versus Austrian 40-year-old Chen Weixing.
Elsewhere, Zhang's next opponent Jiang almost became the second big name to fall to world number 77 Kim Hyok-Bong.
Kim had earlier secured the result of the morning when he delivered a remarkable success for DPR Korea over rivals Republic of Korea, beating world number 10 Joo Saehyuk.
He looked certain to repeat the trick as he moved into a 3-1 lead versus Jiang, only to have no answer as his opponent took the next three games, including the decider 15-13.
While the rest of the star names were struggling, number two seed Wang Hao - a silver medallist at Beijing 2008 and Athens 2004 - was easing to a straight-games win against Singapore's Gao Ning.
The evening was rounded off by victories for Taiwan's Chuang Chih-Yuan and Japan's Seiya Kishikawa.
Meanwhile, in the women's Singles, Japan's Ai Fukuhara produced a stirring fightback to set up a mouth-watering women's Singles quarter-final against favourite Ding Ning.
Fukuhara was given a real scare by the Netherlands' Li Jie, who at one stage held a 3-1 lead at the ExCeL Arena.
That, however, sparked Fukuhara into action and, amid some glorious rallies, she found the necessary power to take the next three games 11-5, 11-8 and 11-8 and book a contest with world champion Ding.
'I feel very comfortable in London,' Fukuhara said. 'I would love to win a medal. I am really grateful to all my supporters and I would like to deliver the best result for them.'
Ding produced another dominant display as she cruised through with a 4-1 win against Hong Kong's Jiang Huajun, while fellow Chinese star and second seed Li Xiaoxia also came up against few problems as she swept aside Park Mi-Young 4-1.