Hough looked classically handsome in black vest, white button-down and black tie, and Irwin, who looking striking in a shimmering, pale-purple gown, began the dance blindfolded with a silk cloth.
Performing a perfectly timed, passionate Viennese Waltz set to "Roses and Violets" by Alexander Jean, Irwin and Hough delivered their most arresting, mature performance of the entire season.
Before their dance, we got to see how the mounting pressure of being the season front runners was affecting Hough and Irwin when it came to choreographing their dances and mastering their steps -- but it's clear from their breathtaking dance that the pressure has done nothing but up their game even more.
Irwin and Hough were once again rewarded for their talent and effortless brilliance with a perfect score.
Later in the episode, Irwin and Hough had to team up with Mark Ballas and Alexa PenaVega for a show-stopping rendition of the classic song "All That Jazz" from the musical Chicago -- and it was simply Broadway-worthy.
With Irwin playing Roxie Hart and PenaVega playing Velma Kelly, the flapper dresses, black bowler hats and short bob wigs were all on point, and the two stars would have given Renee Zellweger and Catherine Zeta-Jones a run for their money.
"It's not very often that I say this, but I wish I was in that number with you!" DWTS judge Julianne Hough gushed when giving the group feedback after the routine. Needless to say, Irwin, Hough, PenaVega and Ballas racked up a perfect score.