Bindi Irwin says words can’t describe how proud she is of her brother Robert, after his US Dancing With the Stars win a decade after she took also out the competition.

The 21-year-old Australian conservationist and his professional partner Witney Carson lifted the show’s mirrorball trophy on Tuesday night (US time) after battling it out against Alix Earle, Jordan Chiles, Elaine Hendrix and Dylan Efron.

“My sister said it best: thank you for changing my life!” an emotional Robert said in the moments after the result was announced to millions of American TV viewers.

Carson, 32, said: “I’m so grateful for Robert, honestly – I already feel like I won with him as my friend and I can’t thank you enough.”

In the three-hour final, the pair performed a cha-cha to DNCE’s Cake by the Ocean.

An excited Bindi posted her congratulations to her brother to Instagram shortly after his win, accompanied by a picture of the siblings clutching their matching trophies.

“TWO MIRRORBALLS NOW CALL AUSTRALIA ZOO HOME!!!! she wrote.

“Congratulations and all the love in the world to Robert Irwin and Witney Carson. What. A. Night.”

The siblings – the children of the late Crocodile Hunter Steve – and their mother, Terri, have been in the US together while Robert performed in the show.

The finale also brought the return of the previously-eliminated couples from the show’s season 34 to dance to Tyler, The Creator’s Sugar on My Tongue, Lady Gaga’s Applause, and I Don’t Dance by Alexander Jean, while season 33 champions Joey Graziadei and Jenna Johnson reunited for a routine soundtracked by Fabio Hager Sexteto’s Tanguera.

Co-host Alfonso Ribeiro revealed the finale had broken several Dancing with the Stars records.

More votes were cast for the top two celebrity entrants, Irwin and Earle, than any top two in the show’s history and the difference between them was closer than ever.

More than 72 million votes were cast during the finale, and more than 500 million in total throughout the series.

A few weeks ago, Irwin claimed he “almost died” during the team dance after accidentally inhaling a piece of confetti.

“I almost died tonight,” he told Entertainment Tonight.

“I choked on a piece of confetti after the team dance. I went over to Witney, and I think they cut away, and I inhaled a piece of confetti. I couldn’t breathe.

“I went over to [Carson and showed I couldn’t breathe], and then I just went, ‘Ugh!’ And it just popped out! I’m not even kidding!”

Irwin said he was grateful to have had Carson as his dance teacher.

“The amount of trust I feel for Witney is insane. I feel like this little team we’ve got together has never been stronger, and I’m just so grateful that [Witney] trusts me to take on a new challenge every week,” he said.

“It’s a dream come true to find new sides to myself.”

—with AAP