Tan had to be assisted off court in a wheelchair at the Australian Open after suffering calf problems
Serena return had been eagerly anticipated but 115th-ranked Tan ripped up the script with a nerve-shredding win.
Ugo Humbert had 90 minutes to fill before his delayed Wimbledon match against Casper Ruud on Wednesday but it still wasn't enough to pack properly as he turned up at Number Two Court missing a vital piece of equipment - a tennis racket.
IMAGES from Day 6 of the Wimbledon Championships at All England Lawn Tennis and Croquet Club on Saturday.
Serena has slid down to 1,204 in the rankings and needed a wildcard from Wimbledon organisers
Poland's red-hot world number one Iga Swiatek did not drop a game in her Saturday singles match against Romania's Andreea Prisacariu, sending Poland through to November's Billie Jean King Cup finals in decisive fashion.
It was Novak Djokovic's first match this year after his Australian Open hopes were dashed when he was deported following an 11-day saga revolving around his decision not to have a COVID-19 vaccination.
Images from Day 8 of Wimbledon 2022 at the All England Lawn Tennis and Croquet Club in London, on Monday.
Summary of sports events and persons who made news on Tuesday