The soap star, 35, sent the temperature of head judge Shirley Ballas "through the roof" with his hip action during the rumba.
Craig Revel Horwood told Fletcher: "You're obviously in touch with yourself! It was full of machismo. It oozed masculinity. It was filth!"
Motsi Mabuse quipped of Fletcher's professional dance partner, her sibling Oti: "I'm just like, 'Hold on Kelvin. That's my sister. Stop it!'"
Ballas described Fletcher as "a very masculine man, with scintillating and sensual hip action, with a beautiful leg action and sensitivity of touch.
"You just sent my temperature through the roof! I've never seen a man rumba like that," she gushed.
Bruno Tonioli called the actor's hips "weapons of devastating effect" before the pair went on to score 36 points.
Meanwhile, David James stunned judges with his improvement, having survived two dance-offs on the BBC One show.
The former England footballer and dance partner Nadiya Bychkova performed a quickstep on this week's Strictly Come Dancing.
Tonioli quipped: "Did you change your diet? Extra vitamins? That was a miraculous transformation... I'm gobsmacked."
Michelle Visage accidentally bumped heads with her dance partner Giovanni Pernice during their salsa.
She told co-host Claudia Winkleman afterwards: "It was on the last spin. I banged heads with him.
"It was my fault obviously," she said of the mishap.
Mike Bushell and Katya Jones returned to the dancefloor, with a quickstep, after Jones fell last week.
The pair came back with a bang, with 32 points from the judges, leaving Jones in tears.
"Is this a dream? Is this real?" sports presenter Bushell said following the positive judges' comments.
Karim Zeroual and dance partner Amy Dowden closed the show with the tango and got three judges on their feet.
Judges called the performance inspiring, "the first time we are really seeing a male celebrity lead" and the "best dance of the evening", and the pair topped the leaderboard with 38 points.
Dowden said of her celebrity partner: "He was so nervous. Minutes ago he couldn't remember it."
The night also saw EastEnders actress Emma Barton perform a Viennese waltz, Radio 1 DJ Dev Griffin dance a cha cha cha and Catherine Tyldesley channel her inner Beyonce with the Charleston to Single Ladies.
Anneka Rice and Kevin Clifton left the BBC One show last week.