Mason slid home his third goal in four games after 77 minutes to cap a third win in a row for manager Russell Slade.
Anthony Pilkington netted first in an eight-minute spell in the second half that continued Cardiff's unbeaten start to the Championship season. In stark contrast, Chris Powell's Huddersfield are still looking for their first victory in what looks set to be a long season.
Cardiff were unchanged from the side that won at Nottingham Forest a week earlier as Slade kept faith with his unbeaten lineup.
And they almost found an early break through their in-form strike partnership.Mason was bundled off Peter Whittingham's long ball but the chance fell to Kenwyne Jones, who could only head straight at Jed Steer.
The Aston Villa goalkeeper was one of three players on loan to make their first appearance for Huddersfield, behind Norwich centre-back Elliott Ward and Forest midfielder Jamie Paterson.
Yet there was a lack of spark about Cardiff despite the dramatic improvements this season from last.They lost Lee Peltier early on after the right-back failed to shake off the effects of a crunching challenge by Jonathan Hogg.
It was a bruising opening for Cardiff who also saw goalkeeper David Marshall receive treatment after colliding with his own player to deny Sean Scannell. Scannell out-paced Peltier's replacement and his deflected shot was cleared by Fabio Da Silva. However neither goalkeeper was troubled in a tame first-half
Scott Malone was teed-up by Joe Ralls but his shot was easily saved to Steer's right. The second half proved far more entertaining as both sides chased all three points. Paterson charged at the heart of Cardiff's defence before his shot was blocked by Sean Morrison.
Cardiff striker Jones then missed the chance to score for a third game in a row for the first time since his days in the Premiership with Stoke City in 2011.
The Trinidadian turned Joel Lynch only to fire tamely at Steer and was hauled off moments later. Huddersfield felt they should have been awarded a penalty when Harry Bunn went down under Connolly's challenge
And less than 60 seconds later, Cardiff were in front.Jones' replacement Sammy Ameobi supplied Pilkington, who turned his marker and confidently steered home from six yards out.
Cardiff then grabbed a second just eight minutes later when Mason latched onto Pilkington's through ball
He skipped past Steer before steadying himself to side-foot into an empty net from a narrow angle
Source : PA