Ireland, playing their third Test, were chasing 182 for a famous win, only to be demolished by Chris Woakes and Stuart Broad in perfect conditions for seam bowling.
In the damp and gloom and with the floodlights on at Lord's, Woakes swung the ball for 6-17 and Broad nipped it around for 4-19.
At one stage, three wickets fell for no runs and the last nine for 18 as Ireland registered the seventh lowest total in Test history and the lowest at Lord's.
Woakes and Broad bowled unchanged through an innings that took only 94 deliveries, the joint-second shortest in Test history and shortest for 95 years.
From England's perspective, it was a bowling performance that masked the deficiencies of their batsmen, who collapsed in each innings and were reliant on 92 from nightwatchman Jack Leach on Thursday.
Indeed, their first-innings total of 85 was the lowest to win a Test for 112 years.
With the Ashes against Australia less than a week away, England have done little to allay concerns over their top order, while their fast-bowling picture is increasingly crowded.
England's squad for the first Ashes Test will be named at 11:00 BST on Saturday.
England win but Ashes questions remain
This has been an extraordinary Test, packed almost as full of incident and discussion points as England's glorious World Cup final triumph on the same ground 12 days ago.
In the end, England avoided the ignominy of defeat to the Test novices, but have answered few of their Ashes questions.
One positive is the 72 made by Jason Roy on debut, but opening partner Rory Burns was scratchy and number three Joe Denly spent little time in the middle. Jonny Bairstow and Moeen Ali look woefully out of touch.
Jos Buttler and Ben Stokes, rested for this game, will return but Leach, England's top-scorer, was in the side for his left-arm spin and is unlikely to play at Edgbaston on Thursday.
If England are short of batting options, then they have riches of pace bowlers. Woakes and Broad pushed their claim for inclusion against Australia, while Sam Curran and debutant Olly Stone bowled nicely in the first innings.
With James Anderson and Jofra Archer set to return from injuries, England have six options for three pace-bowling places.
Woakes and Broad demolish Ireland
Stuart Thompson bowled Stone with the first ball of the day to set up Ireland's chase, one that was halted by rain.
When it was dry enough for play to resume, the conditions were about as bad as they could have been for Ireland and perfect for England. Woakes, who has an outstanding record on this ground, and Broad took advantage.
On a full length, they exposed Ireland's techniques and lack of experience, nibbling the ball around to either find the edge or pepper the pads.
England's catching was sharp, perfectly demonstrated by wicketkeeper Bairstow diving to his left to hold William Porterfield off Woakes for the first wicket.
What followed was an exhibition of seam bowling to which Ireland had no reply. Their defence was flimsy and those who tried to hit their way out of trouble found that it was not the answer.
Pride in defeat for Ireland
Although Ireland were taught a harsh lesson on this third day, they can leave Lord's knowing they gave England a scare.
Yes, their second-innings batting shows how much work they have to do to win Tests, but they had the better of the first two days.
In any other conditions, they would have perhaps begun Friday as favourites to win.
Medium-pacer Tim Murtagh was superb in taking 5-13 on the first morning and he was ably supported by new-ball partner Mark Adair, who was playing his first Test.
On Thursday, when England looked like batting Ireland out of the game, the visitors showed admirable guts and persistence to drag themselves back into the contest.
They will improve through more exposure to Test cricket, with their next assignment coming in Sri Lanka in early 2020.
'Now we can really start focusing on the Ashes' - what they said
England captain Joe Root on BBC Test Match Special: "We still managed to find a way to win and that shows great resilience, courage and unity. Now I feel like we can really start focusing on the Ashes."
England coach Trevor Bayliss: "The way we played today was top class. The first two days we were embarrassed by how we played.
"Our backs were against the walls today and conditions were helpful. In those conditions Woakes and Broad are top class."
England's Stuart Broad: "Both me and Woakesy would roll these conditions up today and take them everywhere with us. You fancy defending anything in these conditions.
"The biggest part of this match was us picking up 10 wickets on day one because if Ireland had got a huge lead that would have been it. A lot has happened in two and a half days!"
Ireland captain William Porterfield: "It all happened pretty quickly - they exploited the overcast conditions.
"All the dismissals were lbw, bowled or caught by slip or keeper - the exact dismissals a bowling side is looking for on that pitch in these conditions. It's a big learning curve for the lads."
Player of the match Jack Leach: "It is bizarre. I bowled three overs for 26 and won man of the match. It has not sunk in. The whole game is a bit of a blur."