It was perhaps for the best that Willie Mullins did not make it to the top of Ayr’s grandstand in time to see the first 30 seconds of the Scottish Grand National. Mr Incredible, the shortest-priced runner among his six-strong challenge for the richest race left in the 2023-24 jumps season, in effect refused to race, while another, We’llhavewan, unseated his jockey at the first. And even as Mullins’s six-year-old Macdermott flashed past the winning post neck-and-neck with Surrey Quest, the trainer’s first instinct was that his horse had been touched off.

Related: This year’s Grand National looked and felt like a better race, in every way | Greg Wood

When the judge blew up the photograph, though, it showed that Macdermott and Danny Mullins had scraped home by a nose at 18-1, while the three other runners from the yard that made it to the second fence eventually finished fourth, fifth and sixth. In all, the Scottish National alone added around £130,000 to his prize money haul in the UK this year, and moved Mullins to the verge of becoming the first Irish trainer since Vincent O’Brien in 1954 to win the British National Hunt championship.

Having trailed Mullins by £31,000 on Friday morning, Dan Skelton, also trying to win the title for the first time, went into Saturday’s card with a narrow lead in the three-way race, thanks to a 285-1 treble on Friday’s card here. Paul Nicholls, who came from out of the clouds to pip Mullins to the title in 2016 thanks in large part to Vicente’s win in Scotland’s most valuable race, was also in the hunt.

The top two positions were swiftly reversed, though, as Sharjah, previously most familiar to punters as a Grade One-winning two-mile hurdler, came with a smooth run in the home straight under top weight to win the card’s three-mile handicap chase.

By the end of the afternoon it was a rout, as Mullins added further wins with Chosen Witness (16-1) and Quai De Bourbon (8-11) to complete a 4,443-1 four-timer on the card.

Stratford-On-Avon 1.10 Villainess 1.40 Twp Stori 2.15 Lady Gwen 2.48 River Tyne 3.23 Avada Kedavra 3.55 Raise Your Glass 4.25 Deise Aba

Wincanton 1.22 Wavering Down 1.57 Irish Hill 2.32 Mirabad 3.02 Manuelito 3.35 Inflexible 4.07 Guillaume 4.37 Celtic Dino

Musselburgh 3.45 Whisky McGonagall 4.15 Do It Now 4.45 Hougomont 5.15 Plus Point (nb) 5.45 Individualism (nap) 6.15 Abduction 6.45 Glorious Angel

The only bookie still offering odds on the title race had Mullins at 1-50 and, while there is plenty to be won on the Jumps Finale card at Sandown Park next weekend, the championship belongs to the Irishman at the end of a season in which he has also won the Champion Hurdle, Gold Cup and Grand National and become the first trainer to have saddled 100 winners at the Cheltenham Festival.

“That’s one photograph that I’ll be taking home with me, I think,” Mullins said after Macdermott’s last-gasp success. “I thought he had it won, and then in the last stride, I thought we were done. We’re were on the right side of one at Cheltenham and we’ve been lucky in photographs this year, but we’ve been on the wrong side of plenty of them too.

“All my owners have been behind us, saying bring the horses over and try to run them wherever you can and get this job done, so I think we’re three-quarters of the way there now. I’d imagine we need to keep going just to not let someone back in.”

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It remains to be seen whether some or all of the many horses Mullins has entered around the country over the next few days actually board the ferry. But even if Mullins declines the chance of a lap of honour, and keeps his horses fresh for Punchestown later this month, his achievement in emulating Vincent O’Brien in the 1950s and, more recently, Aidan O’Brien’s six UK Flat championships from an Irish base, is one of the finest of his career.

Mullins is already thinking about next season, when Macdermott has a host of possible targets. “He’s only six and his best years will be seven, eight, nine,” he said. “The way he jumped today, I think he has Aintree written all over him and we could bring him to Paris for the Grand Steeple [de Paris, in May]. When you win, you’ve all sorts of plans.”