Craig Grylls rode Pure Champion to third place, three-quarter length ahead of Abidewithme and Matthew Cameron who had a nose advantage over Shuka and Mark Du Plessis.
"It is [a fairytale] but this is one we had to get done [because] it's probably her optimum distance and what she's potent at - the 1400m so the pressure was on to get it out of the way," Sharrock said as I Do, named after the Gin Wigmore song, won her first Group 1 crown.
While the mare came into the race with a non-Group 1 pedigree, she had to carry the burden of wearing the favourites tag.
"The public said we deserved to win the race so we got the job done and I thought she could."
In keeping with the Daffodil Day theme, the Sharrock and Chittick families donated $2000 each to the Cancer Society.
"Being Daffodil Day and how Lisa [Chittick] suffered her death. It's just been an emotional ride for us in the past two wins," he said after I Do won the Group 3 Foxbridge Plate, named after Lisa Chittick, a fortnight ago in Te Rapa.
Co-breeder/owner Mark Chittick's wife, Lisa, lost her battle with leukaemia three months ago.
Lisa was the sister of retired champion jockey Lance O'Sullivan who was there on Saturday.
Hawke's Bay Racing general manager Jason Fleming said the meeting had raised $13,000 from the day's gate takings for the charity.
During the presentation Mark's father and stud owner, Garry Chittick, was overcome with emotion, handing over the microphone to wife Mary after a few words before dabbing tears streaming down his face to hug Sharrock.
"Yeah, Garry broke down, mate. There's a lot of memories so it's great," Sharrock said.
His instructions to Bosson were uncomplicated.
"I wanted him to be near speed because I had the feeling John Bary would go slowly early in the race," he said of the champion Hastings trainer whose horse Recite and rider Danielle Johnson shot out of the barrier to set the pace but dropped off to finish last.
"He [Bosson] rode her [I Do] perfectly. It was a magic ride.
"He was tight at the 300m mark, extracted himself and got the job done."
Bosson, Sharrock said, was a great friend and a "little champion".
He intends bringing I Do back for the 1600m Windsor Park Plate in a fortnight.
"She deserves to. Then we'll race her for the rest of the season and then mate her the year after.
"We'll let her enjoy the ride and have a bit of fun."
Sharrock said the rain threatened but they didn't need it in the end on a dead-5 track.
"She's a very good horse, mate."
I Do, the daughter of No Excuse Needed, registered her 15th win from 34 starts to boost her stake earnings to $473,725 from the $120,000 win on Saturday.
Bosson said I Do was always a good horse and was now "top of the class".
The confidence never waned in her ability to pull it off because I Do had already beaten many of the former group one winners at the Foxbridge Plate.
Ironically Bosson rode Survived to victory in the same race last year although Bary doesn't train the horse. Bay trainer Kelly Burne trained Survived who finished 13th.
Sacred Star was 10th, with Nashville and Scapolo behind the gelding.
Bosson said Sharrock had given him the licence "to do whatever I liked, really".
The race had panned out exactly as they had intended, the jockey said before making a beeline for the airport.
He did not saddle winning mount Ryan Mark in the race before, the 1200m Swiss Ace Sprint, because he has been grappling with weight issues.
Johnson jumped into the saddle in making the 56kg grade.