Viewers dubbed her "stunning" and "beautiful" as she competed in the game show, running around in bright orange sportswear.
"Only Michelle Keegan could still look absolutely stunning kicking about in a bright orange top, trackies and her hair stuck up," wrote one fan on Twitter.
Viewers dubbed Michelle "stunning" and "beautiful" as she took part in the game show
Another agreed, tweeting: "Michelle Keegan would still look good if she dressed up in bin bags, absolute 10/10, 100% worldie!"
"Michelle Keegan is beautiful...." another wrote, while someone mused: "If Michelle Keegan got locked into a room, I would move heaven and earth to get locked in with her. Is that against the rules? #CrystalMaze."
The former Coronation Street star was making a one-off appearance on The Crystal Maze for Stand Up To Cancer.
Michelle, who is married to radio host Mark Wright, took on the challenges alongside footballer Rio Ferdinand, radio DJ Sara Cox, comedian Josh Widdicombe and Paralympian Jonnie Peacock. The special was hosted by Stephen Merchant.
The group of celebrities were put through their paces in The Aztec, Medieval, Futuristic and Industrial Zones before stepping into the iconic Crystal Dome.
Rather than win a day out at an adventure park, or the booby prize of a replica crystal, the stars played for time in the Crystal Dome – the gold and silver tokens they collected raised money for Stand Up To Cancer.
The actress competed alongside Josh Widdicombe, Jonnie Peacock, Sara Cox and Rio Ferdinand
It's been 21 years since the adventure game show aired on screens.
Stephen said of his role: "As a huge fan of the original series, I'm honoured to support Stand Up To Cancer by hosting this one-off edition of The Crystal Maze. Richard O'Brien and Ed Tudor-Pole leave big shoes to fill, but I have size 14 feet, so I'll do my best."
At its height, The Crystal Maze was the most-watched show on the channel and regularly pulled in between four and six million viewers. It first aired in 1990 for five years.