The head-to-head debate saw the Tory leadership hopefuls row over the economy, taxes and Boris Johnson - prompting more than a few heated moments.
But Ms Truss’ allies have now suggested Mr Sunak went too far - citing his frequent interruptions of the Foreign Secretary as “aggressive,” “shouty” and “unbecoming.”
So what does ‘mansplaining’ mean, and why has Rishi Sunak been accused of it?
What is mansplaining?
The Merriam Webster dictionary defines ‘mansplaining’ as:
“to explain something to a woman in a condescending way that assumes she has no knowledge about the topic”
Similarly, the Cambridge Dictionary describes the term as:
“the act of explaining something to someone in a way that suggests that they are stupid; used especially when a man explains something to a woman that she already understands”
What has been said about Rishi Sunak?
Tory MP Jackie Doyle-Price said: "Most women MPs have been subject to mansplaining and being talked over in debate.
“Never a worse example than right now on the BBC."
A spokesperson for Ms Truss told The Times: “Rishi Sunak has tonight proven he is not fit for office.
“His aggressive mansplaining and shouty behaviour is desperate, unbecoming and a gift to Labour.”
Meanwhile, Simon Clarke, who is supporting Ms Truss, condemned Mr Sunak for “some pretty aggressive moments” and “interrupting [Ms Truss] as she tried to set out her case.”
The chief secretary to the Treasury concluded however that “by and large, I think the debate was held in a reasonable spirit reflecting the importance of the issues.”
Those who have defended Mr Sunak include former cabinet minister David Davis, who has publicly announced his backing of the Richmond MP.
He commented: “Sometimes it’s important to intervene in debates.
“When we’re in the [House of] Commons we have these comparatively fierce exchanges lots of times, all the time.”
He also explained why he has thrown his support behind Mr Sunak: “This is a debate to find the prime minister of this country.
“Facing a time when the decisions are going to be really tough … We need the person who a) knows what he stands for, b) is courageous enough to take the difficult decisions and c) is determined enough to do it. And that’s Rishi Sunak.”
Mr Clarke on the other hand shared with Times Radio why he believes Ms Truss to be the right choice.
He said: “Crucially we have to go to the heart of this question. Do you believe the tax cuts grow the size of the economy? Do you believe that they are in themselves something which can create more fiscal space by growing the underlying economy?”
“The answer to that as a Conservative must be yes. And that is the point that Liz is making.
“We’ve got to break with the orthodoxies which have frankly held us back for too long. And we’ve got to get back to the principles which drove the [Margaret] Thatcher government, which is that a lower tax economy is a good in its own right.
“And that is what Liz is pressing.”
What has the public’s response been?
Polling after the debate put Ms Truss ahead of Mr Sunak with Tory party voters.
Although a snap poll by Opinium, based on a sample of 1,032 voters, found that 39% believed Mr Sunak had performed best compared to 38% for Ms Truss, Tory voters split 47% to 38% in favour of the Foreign Secretary - and as those voting in the election, this is the crucial statistic.
Many viewers also took to social media to share their opinions on the two remaining candidates, with several echoing the words of Ms Truss’ allies.
@DomBres wrote: “Only a few minutes in & already fed up of Rishi Sunak.
“Constantly interrupting. Shouting down a woman, even if it is Liz Truss, is not a good look.”
@JRsArmchair added: “Waiting for Sophie Raworth to interrupt the Rishi Sunak show.”
Others however took aim at the Foreign Secretary, suggesting she was painting her own party in a negative light.
@ArgyleLoz said: “Yet again Liz Truss is slagging off her old school in Roundhay and the lack of opportunities they were denied, under a Conservative govt, oh dear.”
Meanwhile, some launched attacks at both candidates - instead calling for a general election.
@13sarahmurphy said: “Ugh. Sunak is so up himself and Truss is a rambling, unprincipled, [Boris] Johnson-loving twit…
“Let’s have neither. We don’t deserve any more of this sh*t. General Election instead please.”