His Rich Hill Mile performance followed a close second on an unsuitable wet track at Te Rapa last month and Brennan said she couldn't be happier with the Per Incanto six-year-old.
"I'm very happy with his progress since the Rich Hill and Matt (Cameron) wants to stick with him which is a boost," she said.
Sword In Stone was added to Brennan's artillery following his huge effort to quit maiden ranks second-up over 1600m at Ellerslie on Sunday.
"He's nominated for the Derby and he'll take another step forward on to it in the Waikato Guineas," Brennan said. "If he runs well in that we'll press on for the Derby.
"He's bred to stay and he's got a good turn of foot. I think he'll be a nice 2000m to 2400m horse."
The Redwood 3-year-old had won his two trials for Brennan and finished a close second behind Lite My Cigar on debut at Te Rapa last month.
On the strength of that Te Rapa effort he was favourite on Sunday, but he had to be extra good to win after he dwelt at the start and settled in the rear group.
"It didn't go to plan," Brennan said.
"We thought maybe he'd be fourth or fifth, but he didn't break (from the barrier) as well as usual and Shaun (McKay) had to sit back and ride him patiently."
Sword In Stone inched closer approaching the home turn then was momentarily held up at the top of the straight. Once clear and balanced, he flashed home through the centre to win by a length and a quarter with McKay easy on him inside the last 50m.
Sword In Stone was a $33,000 graduate from Bradbury Park's draft at the 2017 New Zealand Bloodstock Select Yearling Sale when bought by Singapore-based trainer Stephen Gray on behalf of his Singapore owner, Paul Hickman.
"Stephen trains for Paul in Singapore and we pre-train most of Paul's horses," Brennan said.
"We had English Gambler for him before he went over to Darren Weir in Australia."
English Gambler recorded two wins and four seconds from six starts from Brennan's stable and now Sword In Stone looks an exciting replacement in Brennan's team.
Vigor Winner, a son of Declaration Of War, has also looked special. He is unbeaten in three public appearances, having won two trials before cruising home by three and a half lengths on debut at Hastings.
"He's Hong Kong-owned but has his issues," Brennan said. "He's failed the vet a few times. That's why he's staying here.
"He's smart, but he's a work in progress and I want to space his races. I also originally trained his mother, Savont, and she was a bit quirky, too."
Savont, a daughter of Exceed And Excel, won two sprints and is a granddaughter of Palia, whose four wins included the Group 3 AJC Emancipation Stakes (1500m).
Vigor Winner was bought from the 2017 Ready To Run Sale at Karaka from the Regal Farm draft for $50,000.
- NZ Racing Desk
