Is Boris the first big hitter of London 2012?
At one stage, he couldn't remember the old saying of 'cutting your coat according to your cloth' and turned to his adviser Neale Coleman for help... prompting lots of laughter in the Margaret Thatcher room in Westminster's Portcullis House - which for a select committee is a rare event!
When someone can forget a cliché and still get laughs, you know he is a star.
Boris was keen to emphasise that he is determined to keep costs in check, make sure that the budget of £9.3 billion is not exceeded, stop London rate payers paying a penny more than agreed and at the same time stage a Games just as good as Beijing, at less than a quarter of the cost.
In the process he praised Beijing but also described it as intimidating, claiming London would prove a great spectator experience, with fans entering the London Olympic Park getting a handheld device, or to use Boris's phrase, "a gizmo", to tell them what is happening and where.
His most revealing comments came when asked about the post-2012 use of the Olympic stadium and the whether the media centre might be temporary, in order to claw back some of the £400m allocated for it.
Two weeks ago when I wrote that possible Premiership use by West Ham was back on the table and talks were ongoing, there were a lot of denials.
But Boris confirmed that all options were being looked at, that a Premier League club using the Olympic stadium was certainly an option, but also that it was difficult to square the circle of athletics use with Premier League football.
When an MP asked about housing the media in vacant office buildings instead of a new media centre, Johnson did warn that this might not be practical. Not wise he said to upset the media (he knows he is still one of us) - "remember how they rubbished Atlanta", he said. "We don't want that."
But he did not rule out the possibility that the media centre might be temporary, an idea that has been floated, and in the wake of the credit crunch, is back on the agenda. Something which is worrying local authorities who are becoming increasingly concerned about the legacy benefits the Games will bring them.
It would be tempting to conclude that Boris offers up these little gems of information as a result of intense grilling by MPs, but that would be wide of the mark.
The MPs in general showed an alarming lack of sporting knowledge, their questions more concerned with their personal gripes and, of course, what they see as the concerns of their constituencies.
He may have made the odd faux pas on Olympic matters in the past, but here Boris seemed well briefed and well informed when compared to those charged with cross-examining him.
At one point, he was actually asked to go into battle with the International Olympic Committee (IOC) to make the Games country rather than city-based. An unrealistic challenge he politely declined.
But he did also make clear he is not fazed by the strictures of the IOC and not bothered about previous undertakings made on behalf of London.
Given that his predecessor, Ken Livingstone, signed a Host City contract with the IOC minutes after London had won the Games in Singapore back in 2005 on the basis of the promises made in the bid book, that is quite a statement.
Boris versus the IOC - that would be one contest certainly worth watching.