Mark Johnston and Joe Fanning combined to land the Better Odds With Matchbook Betting Exchange Handicap with Londinium.
The Middleham maestro rarely leaves Glorious Goodwood without a winner and Londinium (9-1) was one of three representatives in this mile-and-a-half event.
The three-year-old hit the front with over two furlongs still to run and showed plenty of heart to see off a number of challengers.
Londinium passed the post with a length and a half in hand over On To Victory, with Winston C third and First Nation fourth.
Fanning said: "He's done it very well. I was going so well turning in and he took me to the front.
"With the light weight I thought we'd kick on. In that ground you don't want to be sitting there.
"Mark wasn't worried about the ground and he seemed to like it."
Johnston said: "Joe said he was always travelling really well and that he was cantering at the top of the hill.
"He was torn then. It's a hard decision on very soft ground. On the one hand you think that maybe they won't get home, on the other hand if you lose momentum it's race over. He said he just kicked for home and it was very straightforward.
"He is a horse that doesn't do well away from home. It was a big decision to bring him to Goodwood as he doesn't like being away from his home box.
"I think he has travelled once overnight before the first day he ran and we decided we wouldn't do it again. It was a big decision to come overnight and it has worked out well.
"He is in again on Friday so he might be getting used to Goodwood."
Johnston saddled his second winner of the day as Threading dominated her rivals in the Markel Insurance Maiden Fillies' Stakes.
The previously unraced 12-1 shot travelled well before powering six lengths clear in the hands of William Buick. Your Choice and Pulitzer were second and third respectively.
Cool Sky claimed victory in an attritional Matchbook Betting Exchange Goodwood Handicap.
The Ian Williams-trained eight-year-old was a 25-1 shot for a two-and-a-half-mile contest run in testing conditions and driving rain.
Denmead travelled strongly to the front early in the home straight and was closely pursued by Arthur Mc Bride, Aurora Gray, Taws and Cool Sky.
It turned into a straight shootout between Aurora Gray and Cool Sky in the last half-furlong and it was Josephine Gordon's mount who won the battle by a length and a quarter. Arthur Mc Bride was a clear third.
Gordon said: "It wasn't easy out there. We went a nice even gallop, but you couldn't see much and us Flat jockeys wouldn't be used to going that far!
"He did it very nicely and stayed on well.
"The ground was on the soft side of good yesterday and today the rain has really got into the ground. I'd say by the end of the day it's going to be really hard work, and tomorrow again."
Williams said: "I very nearly took him out as it was so soft, but I thought 'at least they will go through it'.
"Josephine has given him an incredible ride. I said to the boys at home earlier in the week I had a gut feeling about this horse for this race. I don't know why really, but he reminded me a bit of Teak, who actually won this race on fast ground three years ago.
"He wouldn't be a dissimilar horse. He is not a superstar but he is good for the strengths of this race. He has always looked like he has been crying out for further on the Flat and today he proved that.
"I don't think he will be high enough in the weights for the Cesarewitch, but we'll have a rethink what to do with him."