A mistake from Plymouth goalkeeper Romain Larrieu allowed Cardiff to keep up their play-off challenge with a 1-0 win at Home Park.
Dave Jones' side took advantage of Preston North End's slip-up against Sheffield Wednesday to move to within two points of the top six when Steven Thompson scored on 34 minutes.
Plymouth wasted a number of chances over the course of the game, and Micky Evans was the first to be culpable as he shot wide after ten minutes.
Both Cameron Jerome and Riccardo Scimeca threatened for The Bluebirds, with the prolific striker at fault for trying to overcomplicate things when three yards out.
Vincent Pericard then sent another shot wide for Argyle, but their efforts were compromised when Larrieu let a weak header from Thompson slip through his grasp after a cross from Jerome.
Plymouth's wastefulness continued after the break when Mathias Doumbe could only hit the post, and Lilian Nalis and Paul Wotton were also unable to test Neil Alexander.
Substitute Bojan Djordjic fired over with time ticking away, whilst Larrieu attempted to make amends for his earlier abomination with two super saves to deny Jerome and Kevin Cooper.