Crowley claimed victories with Battaash, Motakhayyel and Nazeef for owner-breeder Sheikh Hamdan Al Maktoum as racing took place behind closed doors because of the COVID-19 pandemic.
Ascot, which usually welcomes around 300,000 spectators to the five-day meeting, was limited to jockeys, trainers and officials. Britain's Queen Elizabeth was also missing the fixture for the first time in her 68-year reign.
But Crowley celebrated as Battaash produced a majestic performance with the 5-6 favourite clocking a top speed of 43.4 mph on his way to victory after finishing runner-up the last two years.
"He (Battaash) is a superstar and I'm very grateful to be riding him," Crowley said.
"He has got better as time has gone on. Obviously two years ago at York he completely blew his lid before the race. I think not having the crowd did help today."
Crowley also won the opening Buckingham Palace Handicap on Motakhayyel, before Nazeef charged home in the Duke of Cambridge Stakes.
Circus Maximus, under Ryan Moore, won the Queen Anne Stakes in a photo finish from Frankie Dettori aboard Terebellum.
Dettori responded later in the day to with victory on Frankly Darling in the Ribblesdale Stakes. (Reporting by Hardik Vyas in Bengaluru Editing by Toby Davis)