Breton Rock ended a losing sequence stretching back almost two years after forging through the testing conditions in the John Sunley Memorial Criterion Stakes at Newmarket.
Without a victory since landing the Hungerford Stakes in August 2014, the six-year-old showed he is at his best when the mud is flying to set the record straight in the Group Three prize.
Pulling double entering the final quarter of a mile of the seven-furlong contest, the 11-4 favourite hit the front earlier than Martin Harley had hoped for.
Although the seemingly rejuvenated Adaay pushed the winner all the way to the line he was not for passing, with a short head separating the pair at the post.
The victory completed a double on the day for the Newmarket handler after he had earlier claimed the Fred Archer Stakes with Bateel.
Simcock said: "That's great as it has been a long time since his win in the Hungerford Stakes. He is a consistent animal and is a star.
"Martin will be the first to admit that he got there too soon, but the race collapsed in front of him. It can't be soft enough for him.
"I thought he would win when I saw him pulling double in the dip. He is a horse that doesn't go and win by two lengths, but is quite happy doing just enough.
"We didn't expect to be here at this time of year. We normally give him a break now but our English summer this year seems to suit him. He will go for the programme that is out there for seven-furlong horses."