The bare facts were a one-over-par 73 for a three-under aggregate of 285 that gave her victory by three strokes from Australia’s Karrie Webb and made her the only player in the field to break par.

The figures hardly tell the story. There were times in Matthew’s round yesterday that she looked liable to sink without trace, but just as she appeared to be at her most vulnerable she struck with a devastating burst of three birdies, as glorious as it was unexpected, that left the field trailing in her wake.

There was no looking back. Almost before your eyes, she was transformed from a faltering and fragile 39-year-old who gave birth to her second daughter only 11 weeks ago into the superwoman that she indicated earlier in the week that she would rather people did not call her.

Instead, it was her younger challengers who crumbled, Japan’s Ai Miyazato taking a double-bogey 6 at the 17th at around the same time as America’s Paula Creamer was imploding with her 6 at the last to leave Matthew with a stress-free victory stroll in the sunshine up an 18th fairway at Royal Lytham ringed with adoring spectators.

These magical scenes, moments to treasure, were in stark contrast to a nervous start.

On the first tee, with all eyes and cameras on her, it suddenly looked as if she did not know what to do with her hands. Whether to put them in her pockets, behind her back or dangle at her side seemed difficult to decide.

Her playing partner, the extrovert Korean-American Christina Kim, was like a polar extreme. She bounced on to the tee as if she was on a pogo stick with pigtails swinging freely, dressed in a bright red top and beret that left Matthew’s pink jersey very much in the shade.

While the Scot looked vaguely uncomfortable in the spotlight, Kim’s body language screamed: “Look at me!”

Matthew shook a few hands and included the young scoreboard girl.

“Hi, I’m Catriona,” she said. It was an unassuming moment from an understated champion-to-be. There wasn’t a soul among the thousands on the course who didn’t know who she was.

It was a relief to get going. But with a following wind coming from the right, she overshot the green at the par-3 first and failed to get up and down, missing from six feet. Another shot went at the third, where she missed the green on the left. This was not part of the script.

Whereas on Saturday she hardly missed a fairway with a display of supreme ball control, yesterday she was all over the place. She admitted afterwards she felt nervous, but after that jittery start she scrambled superbly.

The sixth and seventh, both par-5’s that were there to plunder with wind advantage, passed without a birdie. The sixth was not pretty. She pulled her second into heavy rough, did not make the green with her third and needed an outstanding chip to save par.

There were a few shots of that ilk that kept her afloat, and the 10th and 12th were huge. At the 10th, she missed the fairway on the left and then pushed her second into a bush, from where she took a penalty drop and then limited the damage to a bogey with a chip and a putt from eight feet.

Although Matthew was never headed, at that point she was three over par for the day, one under on aggregate, and had been caught by the in-form Miyazato, who won in France last week in the Evian Masters. Things were looking ominous.

Husband Graeme, who is also Matthew’s caddie, played an important role and not just in helping her plot her way around a course with 196 penal bunkers, the most on any major championship course on Britain. He kept reminding her she was in the lead and to keep going.

“I was getting a little anxious, maybe a little bit down on myself, and that really kind of helped,” she said, and she had to dig deep again at the short 12th, where she had her hole-in-one on Friday. This time she missed the green on the left and played a delicate pitch over a bunker on to a downslope and did well to run by only 12 feet and even better to hole the putt.

Had she failed at either hole there is no saying what the outcome would have been.

There was no sign of what was to come when she again missed the fairway on the left from the tee at the 13th. But from there she landed the ball short and allowed it to run up to within 18 feet. Just as she did on Saturday, she holed out, the 18-foot right-to-left putt toppling in with its last roll.

They say you sometimes need luck to win majors, and Matthew’s arrived at the 14th, where she pulled her drive again. She should have been in heavy rough with only a pitch-out as an option, but she found her ball lying perfectly.

If it was a moment of outrageous luck, she took full advantage, drilling a long iron from there over an array of bunkers and on to the green. It is the kind of shot she has been able to practise at home in North Berwick in the five weeks before her return to action just more than a week ago at the Evian Masters.

She estimated her putt at 40 feet, but she took 19 paces from there to the hole and 50 feet might have been nearer the mark. All that matters is that she rattled it in, and for an encore she reached the green of the par-5 15th in two and did everything but hole the putt for an eagle.

With the scoreboards relaying the news that her rivals were capitulating, barring a disaster, she was home and dry. The only anxious moment came when she found a fairway bunker with another drive missed on the left at the 17th, but by then she could afford a bogey.

After a perfect drive and short iron to the 18th, her birdie putt stopped millimetres short. She marked it to allow Kim to hole out before tapping in for the trophy she has been striving to win for all of her golfing life.

When husband/caddie Graeme replaced the flagstick, the flag was mysteriously missing. If it is where we suspect, in the Matthew bag as a dubiously acquired permanent trophy, then no-one would grudge them it.