Gow pen 90
Cardiff City 3
Chopra 4, 80, pen 85
IF Home Park is to become a fortress again, someone is going to have to remember to pull up the drawbridge before kick-off.
Argyle started hesitantly against a side that may well prove to be one of the Championship's promotion-chasers and lived to regret that uncertainty.
Cardiff striker Michael Chopra took easy advantage to net after less than four minutes from an opening that £4m strikers do not pass up.
After that, Argyle matched or bettered their visitors in all departments but could not find the breakthrough to help lay their Home Park hoodoo - 11 defeats last season; a draw and a loss this.
It might have all been so different if Jamie Mackie had not spurned a sugar-coated chance towards the end of the first half, but he did, and it was not.
The Pilgrims also hit the woodwork twice in a second half in which they stretched every sinew before Chopra doubled the Cardiff lead with ten minutes to go.
A third, when Marcel Seip scythed down Chris Burke, was harsh on the Pilgrims, but not bad for Chopra, who completed his hat-trick with a showboating penalty.
Even a late Greens' penalty that reduced the arrears - from debut-making substitute Alan Gow - and saw ex-Home Park favourite Tony Capaldi sent off for handball, could not sweeten a bitter pill.
Argyle's initial line-up showed one change from the one that had gone into battle with Queens Park Rangers the previous Saturday, Luggy opting to start the game with the side that had begun the second half against the Hoops.
That meant on-loan Celtic forward Cillian Sheridan replaced the man he had come on for at half-time of the 1-1 weekend draw, ex-Rangers' man Steve MacLean.
Having been a starter in all three of the Pilgrims' previous games, MacLean failed to even make a seven-man bench that included just one striker - new signing Gow.
Cardiff were forced to make three changes to an already injury-hit squad, having lost forward Ross McCormack, midfielder Stephen McPhail and defender Paul Quinn to injury in their 1-1 draw at Blackpool three days earlier.
Their substitutes at Bloomfield Road - Burke, Gavin Rae and Adam Matthews - kept their places in the Bluebirds' starting line-up.
The visitors began with intent and had already looked threatening before they took the lead in the fourth minute.
Jay Bothroyd, who had had the beating of Krisztián Timár every time in the opening exchanges, made ground on the right and crossed for the unmarked Chopra, who had so much time that he could take stock of Romain Larrieu's position and scuttle a shot past the Frenchman with impudence.
Argyle responded well, with two menacing corners, well defended, with some desperation, by Cardiff's Scottish international goalkeeper David Marshall and his defenders.
However, the Pilgrims looked alarmingly exposed at the back at times, not the sort of frailty to display against a side with the purpose and talent of Cardiff. When Burke broke down the right and crossed into the danger area, Bothroyd ought to have tested Larrieu more than he did so with an ill-judged low-to-the-ground header.
After such a disappointing start, Argyle settled to their task well, shored up the midfield and took the game to their yellow-shirted visitors: Sheridan had a long-range shot which was turned round the post by Marshall, and Carl Fletcher fired in a dipping free-kick which the Cardiff goalkeeper pouched.
Sheridan was lost to the Pilgrims after a heavy yellow card-earning foul by Anthony Gerrard, bringing Gow into the picture for an earlier than expected debut.
Gow was involved in the build-up to what should have been the Pilgrims' equaliser ten minutes before the break as Argyle turned up the pressure.
The ball arrived at the feet of Fletcher, whose low drive was partially blocked by the Cardiff defence. The ball, however, broke to Mackie, eight yards from goal and in the clear. He had to take his shot early, true, but he really should have done better than to stab the ball wide.
Let off, and with their hosts deflated, Cardiff turned the tide. Peter Whittingham and Burke both found sight of goal and asked a question which the imperious Larrieu answered.
A half that never let up for a minute ended with Argyle back on the attack, Gow showing craft to link well with Judge and find angles that had the Cardiff defence grasping at thin air and which offered hope for the second half.
The Greens were inches from being on level terms in the opening minutes after the interval. Jim Paterson, who had worked as hard as anyone in the first period, swung in a cross from the right to the far post where Rory Fallon stretched to head back what might have been intended as an assist but ended up hitting the top of the Cardiff crossbar.
Argyle continued to dominate the post-break play with some swift, controlled passing. Paterson caused Marshall mild concern with a long shot, and Sawyer induced more of a panic from a goalkeeper the Pilgrims had probably decided did not fancy the ball slung at him with what was probably a cross when it left Sawyer's boot.
The flow almost turned fatally when Cardiff captain Mark Hudson relieved pressure with an aimless punt that saw Chopra sprint clear and beat Larrieu to the ball at on the edge of the penalty area.
He could only toe it, however, and, luckily for Argyle, the ball trickled wide.
The more Argyle chased the game, the more Cardiff sensed the prospect of a deciding goal on the break, and David McNamee's block of Rae's stinger was vital.
Sawyer then rattled the Cardiff crossbar with a powerful header from Paterson's corner before Luggy withdrew a tiring Judge in favour of Craig Noone, to the obvious disapproval of some of the Home Park crowd.
Joe Ledley nearly defeated Larrieu with another chip, this time from the edge of the area, before Chopra secured the points for Cardiff with a sharp piece of finishing in front of more than 1,000 ecstatic travelling fans.
Chopra's third, from the penalty spot, was his sixth goal of the season and sent the unbeaten Bluebirds to the top of the Championship.
The Green Army were given something to cheer in the final minute, when Capaldi earned a second booking for a needless handball in the box, and Gow stroked home the penalty.
Argyle (4-3-3): 1 Romain Larrieu; 16 David McNamee, 5 Krisztián Timár, 19 Marcel Seip, 18 Gary Sawyer; 25 Alan Judge (17 Craig Noone 74), 4 Carl Fletcher (capt), 3 Jim Paterson; 8 Jamie Mackie, 14 Rory Fallon, 21 Cillian Sheridan (26 Alan Gow 25). Substitutes (not used): 2 Karl Duguid, 11 Kári Árnáson, 20 Luke Summerfield, 22 Réda Johnson, 23 Kyle Letheren (gk).
Booked: Sawyer 23.
Cardiff (4-4-2): 1 David Marshall; 27 Adam Matthews, 15 Anthony Gerrard, 5 Mark Hudson, 12 Tony Capaldi; 11 Chris Burke, 4 Gavin Rae, 16 Joe Ledley, 7 Peter Whittingham; 9 Jay Bothroyd (29 Josh Magennis 88), 8 Michael Chopra (24 Miguel Comminges 90). Substitutes (not used): 6 Gabor Gyepes, 20 Peter Enckelman (gk), 23 Darcy Blake, 32 Aaron Morris.
Sent off: Capaldi 90 (second yellow card)
Booked: Gerrard 20, Capaldi 29, Matthews 36.
Referee: Russell Booth (Nottinghamshire).
Attendance: 11,918 (1,091 away).
Argyle v Cardiff sponsored by Cross Keys