Cardiff powered their way to a well deserved victory, but the Black Cats were forced to play with ten men for most of the game.
Joachim Bjorklund was given a red card in the 16th minute after bringing down Richard Langley when the Bluebirds' Jamaican international was clean through on goal.
City's skipper Graham Kavanagh curled a low free-kick around the wall and in off Mart Poom's near post to give the Bluebirds a lead they never looked like losing.
Further goals by Langley, Danny Gabbidon and substitute Alan Lee sent City to their first victory of the season over top ten opponents.
Before the match started, there was a minute's silence in memory of Wales legend John Charles, who passed away at the age of 72.
The game exploded in the 16th minute when Bjorklund was sent off and Kavanagh made the visitors pay by netting direct from the free-kick.
It did not take long for the Bluebirds to double their lead with a superbly taken goal by Langley in the 27th minute. Kavanagh won a midfield tussle and flicked the ball out wide to Rhys Weston who was racing down the right flank.
Weston's low cross into the danger area was hammered into the roof of the net by Langley with Poom grasping thin air.
The Sunderland defence were guilty of giving the ball away too easily which kept them continually under pressure and they were playing a dangerous game by using the offside trap just inside their own half particularly when up against someone with the lightning pace of City's Welsh international Robert Earnshaw.
During the interval, Sunderland manager Mick McCarthy took off Kevin Kyle and Marcus Stewart and started the second half with Darren Byfield playing a lone role up front, while Tommy Smith bolstered an overworked midfield.
It all meant nothing however as the Bluebirds went three up two minutes after the restart when a cross from Earnshaw was hooked in by Gabbidon.
Jason McAteer and John Oster tried valiantly to get the Black Cats some reward, but the City midfield were well on top with Langley free to make a number of dangerous runs into the visitors' half.
Earnshaw had two chances on the hour but Poom saved well on both occasions.
Jeff Whitley had a snapshot turned over by Martyn Margetson and from the resulting Oster corner, Gary Breen headed high over the bar in one of Sunderland's few forays into the City half.
McAteer was surprisingly replaced by Paul Thirlwell after 66 minutes and then City boss Lawrence took off Earnshaw and Paul Parry for former Charlton midfielder John Robinson and Andy Campbell.
Sunderland's sub Byfield had a glorious opportunity of reducing the deficit 18 minutes from time, but his low shot was turned aside by Margetson and Tony Vidmar hacked the loose ball clear.
Just as Sunderland looked as though they may get a consolation score it was Cardiff who sent the ball the length of the field and Lee beat the offside trap to slam in the fourth goal just two minutes after taking the field.
Cardiff: Margetson, Weston, Vidmar, Gabbidon, Barker, Langley, Kavanagh, Boland, Parry, Earnshaw, Thorne.
Subs: Lee, Campbell, Prior, Robinson, Alexander.
Sunderland: Poom, Wright, Breen, Bjorklund, McCartney, Oster, McAteer, Whitley, Arca, Stewart, Kyle.
Subs: Williams, Byfield, Thirlwell, Alnwick, Tommy Smith.
Referee: P Crossley (Kent).