Sunderland head coach Gus Poyet believes that Jermain Defoe is a big reason for the team's change in form.
The former Tottenham Hotspur striker signed for the Black Cats from MLS side Toronto last month.
Since his arrival, the North-East outfit have lost once in four games, which Poyet believes is largely down to the 32-year-old's presence.
"He's a wake-up call, we can call it," BBC Sport quotes Poyet as saying. "It's no coincidence that we are winning with him in the side.
"I know strikers are always about goals, but the way he moves, the options he gives us when he makes runs, how good he is on the ball - he gives the opportunity to others to take advantage of that as well."
Sunderland will take on Swansea City at the Liberty Stadium on Saturday.
