Haggas, successful with Green Destiny in 2011 and Danchai 2103, also had Desert Icon in the 22-runner contest – but it was Sinjaari who lifted the prize.
It was a good training performance by the Yorkshire-born handler as Sinjaari had been off for 281 days and was returning to action after being gelded.
Jockey Steve Donohoe brought Sinjaari (11-1) through the pack in the final furlong, with the field spread right across the course.
The Camelot four-year-old showed a decisive turn of foot to head 66-1 outsider Certain Lad and land the spoils by a length. Fifth Position (6-1) was three lengths away in third place, with Dark Jedi (28-1) fourth.
Haggas said from his Newmarket base: “I’m thrilled to bits he’s come back to himself as he lost his way last spring having looked a bit useful.
“What he loved today was the fast pace and I’m sure he appreciated the drop of rain.
“I’m not sure what happened last season. I gave the jockey the wrong instructions at Royal Ascot and after that he wasn’t the same.
“We had him gelded but not because he was naughty in any way, he’s a lovely horse. I wasn’t sure he was coming to himself in time, but just in the last two weeks I thought we were getting him back.
“I wouldn’t know where we’d go with him. I won’t go back over a mile and a half, though – what he wants is a fast pace over 10 furlongs. I’m a bit taken aback by that to be honest to be thinking of what next.
“It’s just great to win a race to win with him – it’s a great race, a race we try to find one for every year.”
Donohoe said: “He loved the ground and saw his race out really well.
“It’s a John Smith’s Cup and it was a tricky enough, but once he got a bit of room up the straight he put it to bed. We were tapped for toe early, but then he came alight. He’s a very kind horse and has a really good attitude.
“With lockdown we’re all taking a hit and it’s good to get a nice winner.”Get your free Racing TV fleece - the latest in our range of high-class Racing TV merchandise! Click here for more details.
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