It was also the most significant victory in the career of Ireland’s champion trainer who was celebrating a record 65th win at the National Hunt Festival.
Runner-up on no less than six previous occasions, Mullins matches the feat of his late father Paddy whose Dawn Run triumphed in 1986.
“I was here when my dad won with Dawn Run and I didn’t get home for two days,” said Mullins after winning the race at the 26th time of asking.
“I sort of resigned myself to never winning a Gold Cup. Certain jockeys may never win the feature race of their lives, like the Grand National or the Champion Hurdle.
“I thought maybe I’m not going to be lucky.”
Al Boum Photo’s win also atoned for an embarrassing blunder at last year’s Punchestown Festival when jockey Paul Townend inexplicably missed out the penultimate fence.
This victory was also the most significant to date in the career of Townend who, since his apprentice days, has been understudy to the mercurial Ruby Walsh.
It was a ride which confirmed that Townend will, in all likelihood, succeed Walsh at Closutton when Walsh finally hangs up the saddle.
Yet it did appear – for much of the race – that the Gold Cup curse of Mullins would continue as the three-and-a-quarter mile race took its toll.
The Mullins-trained Kemboy unseated his rider after the very first fence before stablemate Invitation Only, at the head of the field, suffered a fatal fall at the 10th fence, bringing down the luckless Yorkshire challenger Defintly Red in the process.
With a circuit to go, defending champion Native River and Might Bite – the first two home a year earlier – were resuming their rivalry.
Yet, despite the Walsh-ridden Bellshill among those to be pulled up following a number of significant jumping errors, Al Boum Photo, owned by longstanding supporter Joe Donnelly and his wife Marie, was the only one of the Mullins battalion still in the race as the field turned for home.
Leading at the second-last fence, Al Boum Photo never looked like being headed despite Anibale Fly, trained in Ireland by Tony Martin and ridden by Barry Geraghty, staying on strongly to finish second – the runner-up ran the perfect trial for the Grand National.
Back in third was the Nigel Twiston-Davies-trained Bristol De Mai – the Haydock specialist proved that he now has the maturity to handle Cheltenham’s undulations – with Native River fourth.
Of the other fancied runners, Clan Des Obeaux was fifth for Sir Alex Ferguson – the horse’s time might yet come when he comes stronger with age and experience – while two-time Festival winner Presenting Percy was eighth after never getting into contention. Former King George winner Thistlecrack was pulled up.
Though the death of Invitation Only was a poignant reminder of racing’s risks, Mullins focused on the positives after finally winning the one major race to have eluded him on both sides of the Irish Sea.
Incredibly Al Boum Photo’s only previous run this season was a winning one at Tramore on New Year’s Day – further testament of the ability of Mullins to prepare horses for the big occasion in spite of an unseasonable winter that had seen him unable to run so many of horses because of unsuitably quick ground.
“I’ve got used to the disappointment of finishing second,” he reflected. “I thought Bellshill would take a lot of beating, but Ruby (Walsh) wasn’t happy with him and pulled him up early.
“To have three of the four runners out of the race before they came to the second-last first time round – I was depending on one.
“Every time I looked at Paul, his body language told me was very happy and the horse was relaxed.
“When he came over the last, I just looked at the winning post and thought nothing would come and get him unless he stops or runs out or something like that.”