Ridden by Paul Hanagan for trainer John Gosden, the filly dispatched longtime front-runner and third-place finisher Volume early in the straight and drew off to victory, 3 3/4 lengths clear of Sheikh Hamdan's Tarfasha, the runner-up trained by Dermot Weld.
Taghrooda covered 1 1/2 miles in 2:34.89 on turf rated as good. Favorite Marvellous finished sixth in the 17-horse field.
At 5-1 odds, Taghrooda won her third race from as many career starts after she was entered off a brilliant six-length victory in the Tweenhills Pretty Polly Stakes May 4 at Newmarket in her season bow. She won her debut in September at Newmarket.
Riding in the Oaks for the first time, Hanagan had Taghrooda positioned just off the front-runners and expertly handled her as she was hampered a bit with just over a half-mile run. He asked her to lengthen stride a quarter-mile out and she smartly quickened past Volume, who led after the opening quarter. She was much the best thereafter in an impressive triumph.
Tarfasha accelerated into contention from fifth early in the stretch, and while she was no threat to the winner, she edged past Volume, just getting her nose in front of that rival to take second in the final strides.
Hanagan said though he plotted the race strategy for a long time, he had one anxious moment.
"The race went almost completely to plan," he said. "I've been going through the race in my head for the last month or so, and it pretty much matched what happened today.
"There was one slight scare about five furlongs out when she got a bit of a bump and changed legs coming down the hill. I managed to get her back on the right leg though and she organized herself again pretty quickly."
Gosden praised Hanagan's ride to classic glory.
"Paul rode her perfectly, although she got a bump that put her onto the wrong leg and meant she was leading on her off-fore coming down Tattenham Corner, which is where you don't want to be doing that," he said.
"Cleverly, Paul got her back onto her near fore and she did it well. Two good fillies were second and third, so it looks like a good Oaks.
"I always thought she was a nice filly, but I felt the extra two furlongs was right up her alley, which is why he had her handy. Richard [Hughes, on Volume] was in front trying to ride the race to suit himself and his filly won a trial in that way, so we knew if he was playing with the pace we wanted to be where we could do something about it and use our filly's class. Paul did just that and it was a very smooth performance."
The easy victory marked the third Oaks win for Sheikh Hamdan, who scored with Salsabil in 1990 and Eswarah in 2005, while Gosden and Hanagan captured the race for the first time.
Sheikh Hamdan, deputy ruler of Dubai and the minister of finance and industry of the United Arab Emirates, has 12 classic wins overall.
Gosden was still savoring his classic success two weeks ago at the Curragh when sending out Kingman to win the Tattersalls Irish Two Thousand Guineas (Ire-I).
Taghrooda is out of the stakes-winning Sadler's Wells mare Ezima, runner-up in the 2008 Lancashire Oaks (Eng-II). She is from the high-class Aga Khan family that includes 2013 Ascot Gold Cup (Eng-I) winner Estimate and 1997 Kildangan Stud Irish Oaks (Ire-I) and Prix Royal-Oak (Fr-I) winner Ebadiyla, who is the dam of Ebanoran, a twice stakes-placed son Oasis Dream who will carry the Aga Khan's colors in the June 7 Investec Epsom Derby (Eng-I).
Sea The Stars, Europe's Horse of the Year of 2009, is an 8-year-old son of Cape Cross out blue hen Urban Sea who stands at the Aga Khan's Gilltown Stud in Ireland. Taghrooda is his first group I winner and classic winner.
This year's edition of the English classic was run to honor legendary trainer Sir Henry Cecil, a 10-time champion who won the Oaks eight times. He died of cancer in June 2013.
Inchila finished fourth, a neck behind Volume, followed by Ihtimal, Marvellous, Palace, Momentus, Lily Rules, Madame Chiang, Island Remede, Regardez, Marsh Daisy, Dazzling, Anipa, Honor Bound, and Amazing Maria to complete the order of finish.
Taghrooda's victory was an emotional one for Richard Hills, Sheikh Hamdan's former retained jockey and now his racing adviser. Hills' brother John died of pancreatic cancer last Sunday and the former rider felt his presence on race day.
"This is what we work for and John wished me good luck over the weekend with this horse," said Hills, choking back tears. "He was definitely there with us today. I'm so pleased for the boss (Sheikh Hamdan) and everyone else—it's a big lift for the Hills family."