The Scottish striker struck from close range after Saints had dominated the first period, and the home side could not recover from their half-time losing position.
"We were in control of the game for much of the first half, but the goal changed it," Davis told Saints Player
after the game.
"We got in at half time thinking there was still something in the game for us, but credit to Sunderland – I thought they defended very well.
"They put bodies on the line and, when you've given them something to hang onto, they are going to do that.
"We didn't quite get out of second gear," summarised the goalkeeper.
"We showed flashes and got ourselves into good positions, but we didn't have that finishing touch today.