The Australian hoop has earlier revealed that he will go on a three-month sabbatical from racing to return home to Adelaide, where he will work at his father's wholesale smallgoods shop in Morphett Vale and take over the family business should things work out.
He did not rule out the possibility of a comeback next year, but to "bid farewell" with two seconds and two thirds from nine earlier rides on Saturday, before topping it off with a long-awaited Group win in Singapore with the Ricardo Le Grange-trained Bestseller was what Stewart hoped for.
After a clean jump from barrier one, Stewart was happy to tuck the Dream Ahead four-year-old in fourth behind leader Mr Black Back (Manoel Nunes) while Saint Tropez (Matthew Kellady) and Circuit Mission (Iskandar Rosman) surged to the front to sit in second and third respectively in the backstraight.
Meanwhile, $11 favourite Raising Sixty-One (Bruno Queiroz) sat wide outside Circuit Mission, punching the breeze for most of the 1700m journey. As the field fanned out across the track for the final sprint home, Bestseller was still caught up in traffic behind Mr Black Back.
Stewart tried to duck in at the 350m but could not sneak through with Saint Tropez closing in on his outside. Up front, Mr Black Back held on valiantly while Raising Sixty-One motored home on the outside, seemingly capable of giving the young Brazilian jockey his first Group win at Kranji.
Yet, it was not meant to be because a second gap presented itself for the plucky Bestseller after Saint Tropez faded out. The $20 shot darted through and bore down on Raising Sixty-One for an eventual half-length win.
Relentless (Vlad Duric) came a tad late to run third another one-and-a-quarter length away while Mr Black Back missed the podium finish by another three parts of a length. The winning time was 1 min 45.85secs for the 1700m on the Polytrack.
While Stewart did claim the Group 1 Sydney Cup aboard Selino in 2021 and the Group 3 Gold Coast Guineas with Savanna Amour in 2017, his last Group win in Singapore actually came aboard El Dorado's third Singapore Gold Cup win in 2011.
He also steered the top stayer trained by just-retired Kranji trainer Hideyuki Takaoka to two other Gold Cup wins earlier in 2008 and 2009. A clean sweep of all three Legs of the Singapore Four-Year-Old Challenge in 2009 with Takaoka's Jolie's Shinju in the Group 1 Patrons' Bowl, the Group 2 Singapore Derby Trial and the Group 1 Emirates Singapore Derby were also among his notable wins at Kranji.
A celebratory gesture made just before the line at his first Colonial Chief Stakes win may have lightened his pocket by $500, but Stewart, who brought up a total of 262 wins in Singapore and finished fifth on 32 wins on the 2023 jockey's log, was full of compliments for Bestseller.
It was not without a few anxious moments, though.
"He had a good chance, but the rain came and it's a bit tricky being on the fence. I would prefer to be one-off on the outside," said Stewart, who flies out on Wednesday with his young family.
"I was concerned when we got held up at the 600m, but when the gap came, he quickened very well in the straight.
"I spoke with Vlad before the race and the more we spoke, the more confident I got. He said to ride him like the best horse in the field.
"He's (Bestseller ) very tractable and will continue to mature further. It was a good training effort by Ricardo."
The South African conditioner, who pulled off a brace on Saturday after Great Command ($48) also scored in the $50,000 Nova Strike 2017 Stakes, a Class 4 Division 2 race (1200m) seven races earlier, looked every bit proud of Bestseller's first Group win.
He was also elated with the presence of the promising youngster's owners, Leonardo and Karen Javier, as well as racing manager Jun Almeida at the winner's circle.
"Sandy (Leonardo) and Karen are here today. They flew from the Philippines and it's their first time here. This (their presence) made the win even more special," said Le Grange, who also won the Colonial Chief Stakes with Pennywise four years ago.
"There was a bit of worrying moment when he (Bestseller) looked like he was going to be trapped on the fence, but he's a gutsy horse and that was a great ride from Ronnie.
"I always thought he was very unlucky in the (Singapore) Three-Year-Old series but he's just wonderful to train.
"Drawing barrier one on the Polytrack was not the best place to be and when the rain came, it added more intrigue to the whole thing.
"He's not exactly a Polytrack horse but the gamble paid off. He's like a street dog, always in for a fight."
A runner-up in all three Legs of the 3YO series, the Group 3 Singapore 3YO Sprint (1200m), the Group 2 Singapore 3YO Classic (1400m) and the Group 1 Singapore Guineas (1600m) earlier this year, Bestseller has now won six races and placed six times in 15 starts, raking in more than $350,000 in prizemoney for his connections.