Philip Billing ensured the dominant Cherries took all three points away from Wales with a strike from the edge of the 18-yard box.
The triumph saw Scott Parker's men leapfrog his former side Fulham into top spot after they made it eight games unbeaten to start the campaign.
Cardiff threatened an equaliser late on but have now suffered three defeats in their last four matches.
Parker's undefeated Bournemouth side travelled to the Welsh capital on the back of a hard-fought triumph over QPR.
The Cherries manager made a single change to his starting line-up, bringing Ben Pearson in to shore up the midfield in place of Wales international David Brooks.
Cardiff had fallen to a 1-0 defeat at Coventry last time out which prompted manager Mick McCarthy into three changes.
Both wing-backs Joel Bagan and Perry Ng were dropped in favour of Tom Sang and Ciaron Brown, while Leandro Bacuna overcame a hamstring issue to start in place of Rubin Colwill.
The visitors had to soak up some early pressure before they began to take control. Jaidon Anthony was first to trouble Dillon Phillips' goal when he rounded the Bluebirds keeper and steered an effort on target, but Marlon Pack raced back to clear the ball away.
Ryan Christie pounced on an Aden Flint error to force Phillips into a regulation save midway through the first half before he was booked for preventing a Cardiff breakaway.
Bournemouth commanded 72 per cent of possession in the first period but failed to make their dominance count as the sides headed in level at half-time.
But Parker's side made the pressure pay nine minutes into the second half through midfielder Billing.
The Denmark international had threatened the Cardiff defence from the restart when he headed over from Jordan Zemura's teasing cross.
Bournemouth's other wing-back, Adam Smith, seized the opportunity to head off on a surging run down the right before he picked out Billing for his 54th-minute strike.
The 25-year-old had the time and space on the edge of the box to look up before picking out the bottom corner with an accurate left-footed strike for his fourth goal of the season.
He almost doubled his tally for the afternoon when he pirouetted past Will Vaulks and sent a curling shot just wide of the target - when he really should have played in Christie.
Billing then stung the hands of Phillips with a whipped free-kick after Brown went in late on Jefferson Lerma.
Substitute James Collins headed over from close range as the hosts mounted a fightback, but it was too little, too late.