After the match, Mark Hughes hailed the composure of his Fulham side as they collected only a second away win in the Premier League since August 2009.
The Cottagers' only previous away win this season came at Stoke in December while last term their sole three-point haul came on the opening day at Portsmouth.
Hughes said: "I wasn't too happy with the first-half performance. We were 1-0 to the good but we understood we needed to play better in the second half to ensure we took the game away from Sunderland.
"Thankfully we did and we saw the game out very comfortably. Obviously the second goal was key from our point of view and I never felt under pressure that we were going to lose the game.
"We haven't had that many wins on the road and sometimes you can be a little bit apprehensive and try to protect what you've got and that can lead to a problem but we didn't really demonstrate any tension in our second-half performance.''
Sunderland were unable to field a single striker and their problems were immediately apparent as Ahmed Elmohamady and Steed Malbranque both missed the target from decent positions before the deadlock was broken at the other end.
On-loan Chelsea forward Kakuta was allowed acres of space to collect Bobby Zamora's pass and poke the ball through Simon Mignolet's legs for his first goal in English football.
Sunderland should have hit back straight away but Lee Cattermole struck a tame effort from 15 yards and Sulley Muntari's shot was deflected over the bar.
Things got worse for the hosts 16 minutes into the second half when Steve Sidwell chased a long ball before pulling it back for Davies, and the midfielder then took advantage of some more poor Sunderland defending to make it three in the 73rd minute.
Hughes added of Sunderland's selection problems: "We understood it might be an opportunity for us but it was difficult to prepare because we didn't know who was going to take corners or who was going to get on the end of things.
"We still had to get the job done. They played really well against Wigan with no strikers and scored all the goals in that period so we had to make sure we didn't take Sunderland's predicament lightly and think it was a foregone conclusion.''
Sunderland boss Steve Bruce, who was without 10 players through injury, was left to rue poor play at both ends of the field.
He said: "We created the chances but we needed to take one. Certainly from the midfield areas, Jordan (Henderson) scored two last week and he's had a great chance, (Lee) Cattermole has had a great chance, I think Steed (Malbranque) has had two.
"We needed to give ourselves that cushion and unfortunately the goals we gave away were horrific. Then we were chasing it and we didn't really have anything to chase with and it became one of those horrible afternoons.''
Things are unlikely to change anytime soon for Bruce, with strikers Danny Welbeck, Asamoah Gyan and Fraizer Campbell all set to miss the rest of the season.
He added: "We have to accept it and move on. It's certainly desperation stakes when you're putting someone like Nedum Onuoha up front but it is what it is unfortunately.''