Lights On caused a minor upset in the bet365 Mile at Sandown.
Six runners went to post for the Group Two feature, with much of the pre-race attention focused on triple Group One-winning filly Alcohol Free and the recent Thirsk scorer Mutasaabeq.
There was little to choose between the pair in the betting come the off, with Alcohol Free the marginal favourite at 7-4 ahead of Mutasaabeq at 85-40.
The Sir Michael Stoute-trained Lights On, who won a Listed prize at Pontefract last summer before being beaten in successive Group Threes, was a 17-2 chance in the hands of Ryan Moore.
After racing in midfield for much of the race, the Cheveley Park Stud-owned mare quickened up to grab the lead inside the final furlong and had just enough in the tank to repel Mutasaabeq by a neck.
The runner-up was undoubtedly an unlucky loser, having been stuck behind a wall of horses before powering home once the gap came.
Cheveley Park’s managing director Chris Richardson, said: “The pressure was on a little bit. It is terrific. She is a super filly and Ryan gave her a perfect ride and Michael has done a fantastic job at home.
“The ground is obviously a serious factor and a bit of ease in the ground helped. It is nice we kept the filly in training and she has rewarded us.
“Whether she goes for the Lockinge will depend on the ground – she needs a bit of ease. Ryan said she might stay a bit further and might stay 10 furlongs, so races like the Falmouth or the Sun Chariot will be under consideration.
“We have to wait for the ground – that is the key with her. We have had such a dry spell, you’d hope some rain will come.
“Quite often at Royal Ascot it can be soft, so we will be making lots of entries and dreaming. She has won a Group Two and we are thrilled.”
Alcohol Free was not disgraced in finishing third on her first start since October and trainer Andrew Balding is confident she will improve ahead of a tilt at the Lockinge Stakes at Newbury next month.
He said: “She will come on for the run, which we talked about beforehand. We thought we might get away with it today, but that wasn’t the case.
“She will come on for it and we are looking at the Lockinge. It is a long season ahead. The hood will come off because she is settling better.
“The ground was not an issue. We were just beaten on the day.”