The 27-year-old dancer had just performed a Jive to Tina Turner’s Proud Mary with Alexandra when he fell to the floor.
However, Gorka’s collapse was all in jest as he teased that The X Factor winner was seriously working him hard.
Host Tess Daly said: “Wow, oh my goodness. Oh my goodness. Would you take a look around this room. Incredible performance.
“You are amazing! So much energy. I don’t know how you keep up with her Gorka!”
At this point, Gorka toppled to the ground leaving 48-year-old Tess stunned.
She gasped: “I’m not surprised. I’m not surprised. I’d be like that just watching you. That was incredible.”
Alexandra later broke down in tears after her performance having scored 39 out of 40.
Overwhelmed by the audience reaction, the 29-year-old burst into tears and cried: “I wish my mum was here, I really do.”
Soul II Soul singer Melissa Bell died in August aged 53 following a nine-year battle with kidney failure, which was brought on by diabetes.
Claudia Winkleman comforted her, saying: “You did so well. Your boyfriend and your brother are here too.
“I know, baby, I know. Baby, you did so well and she’d be so proud.”
Strictly Come Dancing continues tonight on BBC One at 7.15pm.