Robert Irwin's fans go wild as he shares an old clip of his time on DWTS doing veteran Valentin Chmerkovskiy's iconic knee walk while shirtless: 'Christmas came early'

Robert Irwin has excited his fans by sharing a Dancing With The Stars US throwback clip, showcasing the fitness and stamina that helped carry him all the way to Mirrorball glory.

The reality TV star, 22, took to TikTok this week to post an old pre-show warm-up outtake from his time on the hit series.

He is seen nailing veteran contestant Valentin Chmerkovskiy's famously difficult knee-walk move.

Dressed in a striking red, matador-style costume, Robert dropped to the floor mid-routine and glided forward on his knees with ease, arms slicing through the air.

The clip was filmed during rehearsals, with other contestants and crew milling about in the background.

'Little did I know this pre-show warm-up outtake would suddenly become very current. Val, you are the knee walk GOAT,' Robert wrote next to the footage. 

Fans were quick to react, flooding the comments with praise and disbelief at his athleticism.

'Christmas came early,' one person quipped.

Meanwhile, a second added: 'You were amazing. I miss you every week.'

'My teenage heart just skipped a beat,' another chimed in, and someone else wrote 'King behaviour'. 

Last month, Robert spoke out about the rib injury that nearly derailed his triumphant US Dancing With The Stars performance. 

A clearly elated Robert and dance partner Witney Carson appeared on Good Morning America following their big win, and the subject of Robert's ribs was high on the agenda.

'You injured your rib, but you pressed on. So, how's the injury now?' co-host Michael Strahan asked.

Robert admitted that although he's on the mend, the injury is still causing him pain. 

'We're getting there,' Robert replied.

'It's painful. But no pain, no gain. It's all good!' 

Robert was quick to praise Witney for adapting their routines to accommodate his injury. 

'We wanted to push through. Witney was amazing in changing up some of the moves that we had to do in there,' he said.

'We had to change on the fly, but our last dance, that freestyle, was our way to say "thank you" to everybody who had been on that journey.'

Robert added that he was used to such maladies, given his history of catching crocodiles.

When co-host George Stephanopoulos asked if he was having trouble breathing, Robert brushed off the suggestion with a classic Australian response. 

'Yeah, but it's all good. It'll be right,' Robert replied.

Robert and Witney emerged triumphant over a competitive field that included influencer Alix Earle, Olympic gymnast Jordan Chiles, actor Elaine Hendrix, and Zac Efron's brother, Dylan Efron.

Lifting Mirrorball Trophies is now an Irwin family tradition, with Robert's sister Bindi, 27, winning the coveted prize in 2015.