The 37-year-old, a five-time winner at the All England Club, wrapped up a 4-6 6-4 6-1 second-round success to mark her 97th main-draw match at the grass-court grand slam – a record for an active player.
The pair also met in the first round of the French Open, when Williams – who has endured an emotional week amid questions over her involvement in a fatal road accident – prevailed in straight sets, but it was a tougher test on this occasion against the world number 55.
Wang fought back from 0-40 down to hold in only her second service game and showed her resilience again when she was broken in game six, hitting back immediately.
The Chinese continued the theme of producing the goods at just the right time, sending down an ace to deny Williams a break that would have left her serving for the set.
And it was the underdog who ultimately got that honour when a wayward Williams forehand gave Wang the break, which was cemented with a hold that afforded her a one-set lead.
"A smile on the face of Venus Williams"
— Wimbledon (@Wimbledon) July 5, 2017
Williams, who reached the Australian Open final this year before losing to sister Serena, refused to wilt and quickly put pressure on her opponent's serve.
That finally paid dividends when Wang was serving to stay in the second set, with a deft Williams drop shot setting up three break points, the last of which was taken with a precise passing effort.
In the decider it was Williams, a semi-finalist at SW19 last year, who moved up a gear as her variety of shot-making came to the fore to set up a third-round match Naomi Osaka.
Williams  bt Wang 4-6 6-4 6-1
Williams – 43/33
Wang – 20/21
Williams – 6/7
Wang – 4/4
BREAK POINTS WON
Williams – 4/15
Wang – 2/8
FIRST SERVE PERCENTAGE
Williams – 62
Wang – 61
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Williams – 83/39
Wang – 63/51
Williams – 99
Wang – 87
Photo: Getty Image (Venus Williams)