The big moment came almost immediately when the referee for the evening asked Julie Etchingham what each candidate would do about the cost of living that grips so many households in this country.
The clearest response came from Mrs. Truss, who began working out tax cuts that she would introduce immediately, much to the horror of the man who was until recently Chancellor.
And it was then that Mr. Sunak apparently decided that he should rewrite the book on what conservatism actually means.
He now described tax cuts as “something for nothing economics that’s not conservative, it’s socialism.”
If any Conservative members were watching on a hot Sunday night, quite a few have to reach for some hard liquor at that time to calm their nerves.
Ms Truss hit back, pointing out that Sunak’s policies caused massive inflation and failed to help people.
She later emphatically described herself as a “straight-talking Yorkshire woman” and said that’s why she felt so uneasy about breaking the manifesto promise about not raising National Insurance that Sunak drove through.
Significantly, Truss also took the lead in suggesting that she would allow “no normal business” with the Bank of England after it failed to stem inflation.
Sunak was shocked and said so.
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But the foreign minister left Sunak stunned as she explained her “political journey”.
“I went to a high school where kids didn’t have the benefits of the school you went to, Rishi.”
Sunak, of course, attended one of Britain’s fanciest schools, Winchester.
She then said it was that experience and the desire to make the lives of children of her background better, “that made me a conservative.”
If that wasn’t a clarion call for the Red Wall, the conservative voice of the working class, then there was nothing.
Going into tonight, three issues had to be resolved.
Firstly, Sunak would remain the outright frontrunner and class performer he appeared to be following Friday’s debate on Channel 4.
Second, Truss would come alive from a flat campaign and make enough arguments for the party’s right to put her in second place against Mordaunt.
Third, and perhaps most importantly, would the surprise thrill of this match knock Badenoch out of the park to blow up the Truss and Mordaunt campaigns?
The answer is that Sunak is now the man to beat, but after tonight’s performance, he will be eminently beaten by anyone with a conservative tax-cutting platform.
Truss’s Thatcher-esque look and gritty performance could be enough to push her into second place now – “I’m not the brightest artist, but I get things done.”
She looked like the experienced adult in the room, although Mordaunt also managed to put in some lines that offered a broader appeal.
Badenoch had a nice comment from Tugendhat “not in the front line” but both were spectators for too much of the match.
Based on tonight, it looks like the Truss vs. Sunak show could turn into a summer extravaganza where the real nature of conservatism itself is up for grabs.