He retired from the show last November after serving as a judge since 2005.
Bruno and Len were friends for over 19 years and appeared on both Strictly and its US counterpart together.
A specially choreographed routine saw DWTS’ professional dancers – including Kym Herjavec, Anna Trebunskaya, Karina Smirnoff, Edyta Sliwinska and Mark Ballas – dancing to Henry Mancini’s Moon River.
The performance was choreographed by the prominent married duo Val Chmerkovskiy and Jenna Johnson, and also coincided with the theme of the week, which was Most Memorable Year.
As the routine finished, Bruno could be seen sobbing as fellow judge Carrie Ann Inaba reached over to comfort him.
In April, Bruno said he was “heartbroken” over Len’s death.
“I will treasure the memory of our incredible adventures and hundreds of shows we did together,” he wrote on Instagram.
Speaking on the morning show Kelly and Mark last month, Bruno said he knew of Len’s illness, which he had kept private.
He got emotional recalling an email Len sent him, explaining that “he would hate me doing this [getting emotional]… he would say ‘get up Bruno, we have a great life and make everyday count and enjoy’ that’s his spirit and we have to celebrate that,” he said.