The William Haggas-trained runner was backed down to 4-1 favourite to win the track's most valuable flat handicap and under a confident front-running ride from Liam Jones, Harris Tweed stretched clear of his 14 rivals to win the one-and-a-half mile contest by five lengths.
Jones said: "I was able to go out and let him bowl along in front and dictate his own pace, and when I asked him at the two-furlong pole he picked up really well. He's progressing very well."
The minor honours went to Gerard Butler's Sing Sweetly (8-1) and Mark Johnston's top weight Corsica (6-1), with the former shading the runners-up prize by a nose.
Tim Easterby's Hamish McGonagall defied top-weight to land the valuable totescoop6 Scottish Sprint Cup.
The 5-1 chance shot out of the gates in the hands of David Allan and was never far off the pace in the five-furlong 50,000 prize.
Striking Spirit came at him hard inside the final 100 yards but Hamish McGonagall was in determined mood and passed the post a neck to the good.
"He really hit the gate running at York last time as well and that has really made the difference to him," said Allan.
"After that he's flat out but he's not going to stop and he just keeps going. The other horse came at me but he won't give it up and he's very tough."
There was drama in the early stages of the contest as Frederik Tylicki parted company with his mount Sea Of Leaves, leaving the jockey with a serious shoulder injury and a spell on the sidelines.
Tylicki's agent Richard Hale said: "He's been released from hospital but he's fractured his left shoulder blade and also dislocated his shoulder, so it was a nasty one.
"He'll go and see a specialist in the next couple of days and we'll find out then how long he'll be out for, but I'd guess it will at least a month or six weeks."
Other winners included Bryan Smart's Excel Bolt, who scrambled to victory in the 25,000 Totepool Edinburgh Castle Conditions Stakes by a short-head, giving his many supporters a few palpitations after they had sent him off the 4-6 favourite. It was a second successive win at the track for the juvenile, who may now appear at Royal Ascot.
Dandu Nicholl's redoubtable Fremen continued his scintillating season by making it six wins out of six in the seller. The biggest surprise was his starting price of 2-1.
Drosselmeyer unleashed a devastating late sprint to win Saturday's 142nd running of the $1 million Belmont Stakes, the third and final leg of US racing's famed Triple Crown.
Perfectly ridden by jockey Mike Smith, 13-1 shot Drosselmeyer surged clear of his 11 three-year-old rivals on the home straight and held off Fly Down to win the mile and a half (2400m) classic by three-quarters of a length. First Dude, runner-up in the Preakness Stakes, held on to take third, a further neck away. "It was a great trip. It was all about getting into the rhythm and we did it," Smith said. "It worked out. It was incredible. It's great to come home."
Drosselmeyer received the traditional winner's garland of white carnations and the $600,000 purse.