After damaging rows over white poppies and anthems not sung, in the House of Commons today Jeremy Corbyn notched up a sorely needed success. His first prime minister’s questions looked like a daunting task at the start: the troops amassed behind their new general sat quietly terrified. But the moment he opened his mouth, Corbyn came across as a sober and puzzled outsider at the Westminster variety show. This harnessed the silence to his advantage, and – as such – put him on the side of a country which holds the Commons in contempt.

The trick, if it can be called that at all, of reading out questions collated from “Marie”, “Steven” and “Clare” about housing shortages and disappearing tax credits, came off effectively. It turned Corbyn into the voice of all those suffering out in the country. Despite David Cameron’s best efforts not to come over as complacent, his overly smooth responses made him sound like a sloganeering salesman.

That was the impression if you sat through the whole half hour; the Cameron slogans may grate less for the majority who only catch brief clips on the news. The bigger doubt is whether Corbyn can repeat the success in later weeks. “People’s questions” could become formulaic, and Cameron will figure out a formulaic response.

Remarks from other MPs today about the nuclear deterrent and shadow chancellor John McDonnell’s record of overly friendly remarks about the IRA are a reminder of how many challenges Corbyn will have in a house where he has few friends. But today he turned his loneliness to his advantage.

How well he did. What a disappointment to all those waiting for calamity in the press gallery above, poison pens poised. Those with tickets to a bare-knuckle, cockfight massacre of an innocent were cheated. It just didn’t happen.

Instead, a dignified and calm man, seasoned by years of parliamentary experience, raised questions of real importance to millions of people, on the housing crisis, on severe tax credit cuts to millions and on the worsening emergency in mental health. The seriousness and sincerity were almost shocking in that den of artifice.

It was David Cameron who was wrongfooted. He absolutely knew he had to turn down the volume and stop the cheap point-scoring, but he couldn’t. Starting out low key, he soon fell into the manufactured mantras and pre-cooked slogans of the day that make his answers so wearying.

It meant that prime ministerial austerities with the truth lacked sharp ripostes: no, £8bn doesn’t begin to cover the NHS crisis; no, social housing is being crippled; and, no, there’s no “parity“ between mental and physical health. But that way lies ya-boo.

Instead, Corbyn kept to the Commons motion he recently signed, to end this “ill-mannered and pointless exchange of insults”. His grownup style may win the attention of the real audience, those voters outside the Commons where his thoughtful questions will have considerably more impact than the PM’s shouty and shifty replies.

It was a battle between the narrative and the discursive. Corbyn, who crowdsourced questions from the public, gave a performance in keeping with his main personality traits – gauche, earnest, direct and engaging. Cameron, who’s been doing this for some time now, was slick in his delivery as he parried the questions with policy and polemic. Cameron mostly rattled off figures while Corbyn mostly told people’s stories: Cameron held his own in the chamber, but I think Corbyn came off better in the living room.

The expectations for Corbyn were low. He had to do two things. Given the claims made of his campaign he had to be different – you can’t say you’re going to represent a new kind of politics and then start braying, taunting, preening and jeering from the dispatch box. Given the chaotic first few days of his leadership, he could not tank. The first 72 hours have seen too many unforced errors.

Thankfully, he managed to exceed them easily. For a man who is supposed to be out of touch with the public, he appeared connected; as a leader supposed to be a threat to national security, he was measured. Let’s hope one does get a second chance to make a first impression. Because this did justice to his campaign in a way that the last few days have not.

Only Jeremy Corbyn could radically change something to make it more bland. His new approach to PMQs, to read out questions sent in by supporters and members of the public, was fine – but only fine. Fine in the sense of plain porridge, or a grey day on which it neither rains, blows nor shines. Fine because he survived intact, while Cameron was given a safe platform to talk about how well the government is doing. There was no sign of real scrutiny in the proceedings.

If he gets good advice, Corbyn will sharpen it a bit in future – using the guest question as an introduction, but following it up with more pressing queries. If he doesn’t, then it’s hard to see anyone tuning in for more of this. For all the griping about the bearpit approach to PMQs, even Punch and Judy politics is preferable to such a dishwater debate.

The fact that Jeremy Corbyn has steadied the ship with his PMQs performance was undoubtedly important in the context of his first week as leader. But of far more significant long-term consequence was his new, ground-breaking technique of putting questions from members of the public direct to the prime minister. Yes, many found the exchanges dull and undemanding for Cameron to deal with, but today was all about establishing the technique safely and successfully. Now the real fun can start.

It should lead to an explosion in the number of questions Jeremy Corbyn is sent before each session. It was 40,000 this week. By the time parliament returns after conference season, I would guess they’ll have at least 200,000 to play with.

Every time Jeremy Corbyn has an “open goal” it will make it much easier to score. When his government was under pressure over an issue over the past five years, Cameron ignored Miliband’s questions and went on the counter-attack. That is impossible if Corbyn is presenting six questions from the public in a calm, measured style.

Finally, it hands the Labour leader the chance to spring ambushes. Cameron will turn up each week expecting the usual round of topical and popular issues raised by Rita, Sue and Bob too. Once every few months, Corbyn can ditch the script and surprise the PM by forensically questioning him on some obscure but important issue for which Cameron is entirely unprepared.

The new Labour leader’s PMQs technique is an innovation rich with possibility, and – not before time – his second big success of the week.