Judge pen 13, Árnason 60, Judge 62, Barnes 82
KÁRI Árnason became the 500th player in Argyle history to score a league goal for the Pilgrims as those of us who had been dreaming of a Green Christmas had our wishes well and truly granted.
Árnason's landmark strike - his first for the Pilgrims - came in a five-minute frenzy midway through the second half, which Argyle had begun with a slender 1-0 lead given them by Alan Judge's early penalty.
The Icelandic international headed home in the 60th minute, only for Reading to pull back to 2-1 immediately as Gyfli Sigurdsson - another Icelander - netted his second goal in as many games.
Argyle's response to conceding was even swifter than their opponents had been, with Judge heading home a cross from the impressive Chris Clark to restore the two-goal lead.
Add in two bookings, for disgruntled Reading players, and it was, indeed, a mad 300 seconds.
Greens' substitute Ashley Barnes added a late fourth with his second goal for the club as the Pilgrims scored more than two goals in a game for the first time since April
Having piloted Argyle to a first win under his stewardship on Boxing Day, the Pilgrims' head Mariner stayed faithful to the starting line-up that had begun the 1-0 victory in Cardiff.
That meant a first home start of the season for Luke Summerfield, recalled in Wales after completing a productive loan spell at Leyton Orient and therefore absent from Home Park since mid-September.
Otherwise, it was 'same again, please'. Benin international centre-back Réda Johnson was given leave by his country to join them late for African Cup of Nations duty, meaning he could continue his increasingly impressive partnership with Árnason.
With three of his countrymen in the opposition line-up, it was quite possibly the largest number of Icelanders seen on the same pitch since the last Icelandic international game.
On-loan defender Darcy Blake, unavailable to play against his parent club, was the only change in the entire Argyle 18, coming on to a bench that also included Chris Barker, for what might yet be the last game of his in and out temporary spell at Home Park.
Reading, fresh from three successive 1-1 draws, made one change, replacing bean Pole GrzegorzRasiak with Simon Church, who had been serving a one-match suspension when his team-mates secured a point at home to Swansea two days before.
Church had scored the Royals' late equaliser in their previous game, at Bristol City, after which he had received a second yellow card and, consequently, a red.
Incidentally, trivia-heads, his initial caution had been issued while he was warming up with his fellow substitutes, meaning that he was sent off for two incidents, neither of which occurred on the field of play.
The game started at a super lick with Summerfield at the core of much that was good about Argyle's confident early incursions.
On a boggy surface, that cut up from the off, the encounter had many of the hallmarks of a cup-tie. It also produced a comedy moment early on when Church was upended in the Argyle penalty area. By a divot.
A more relevant coming together occurred when Jamie Mackie latched on to a pluperfect channel ball pass from Clark, the unsung players' unsung player.
Brynjar Ingimarsson, one of Reading's Icelandic triplets, was late with his tackle as Mackie pushed the ball beyond him, tripping the Argyle man as Mackie should him a clean pair of Nikes.
Referee Simon Hooper, who had dismissed Blake on his previous visit to Home Park, gave the foul immediately and there was no complaint from the Reading captain, nor from any of his team-mates.
Judge, who had scored twice previously from penalties, showed a similar lack of fuss in converting the spot-kick.
The early goal settled Argyle nerves, though some of their subsequent defending was possibly a little too laid-back for comfort as Reading sought a way back to their current favourite scoreline.
On the rare occasions when they were not defending, the Pilgrims' forward play was sometimes a joy to watch, most notably when a seven-man passing move ended with Mackie sending a sublime header just wide.
At the ridiculous end of the same scale, Argyle were nearly gifted a second as Ingimarsson's nightmare half continued when he nearly turned Karl Duguid's low driven ball into the six-yard box past his own goalkeeper.
For all the visitors' endeavour, it took them until the final minute of the first half to create their first clear goalscoring opportunity, when Jobi McAnuff burst through the middle.
His low shot was powerful and on target, but goalkeeper Romain Larrieu got down quickly to turn the ball aside for a corner.
Reading sent on Jimmy Kebe at the interval to try to gain some width, but Argyle were quick to take advantage of the space it afforded them, and Clark fired a shot against the post after a sweet set-up by Rory Fallon.
The half exploded into life just after the hour, with Árnason giving Argyle the lead, Sigurdsson giving Reading hope, Gunnarsson and McAnuff giving Hooper grief, and Judge giving Home Park relief in the same manic passage of play.
After that, there was time for Craig Noone, Barnes and Yoann Folly to go through their paces, and bolster some tiring legs.
Barnes forced Federici to keep out a fourth by turning a shot, following Summerfield's perceptive pass, around the post before the substitute rounded off a thoroughly pleasing Christmas.
Argyle (4-4-2): 1 Romain Larrieu; 2 Karl Duguid, 11 Kári Árnason, 22 Réda Johnson, 18 Gary Sawyer; 25 Alan Judge (17 Craig Noone 66), 4 Carl Fletcher (capt), 20 Luke Summerfield (31 Yoann Folly 80), 6 Chris Clark; 8 Jamie Mackie, 14 Rory Fallon (24 Ashley Barnes 69). Substitutes (not used): 13 Darcy Blake, 15 Chris Barker, 23 Kyle Letheren (gk), 26 Alan Gow.
Booked: Johnson 37, Mackie 40.
Reading (4-4-2): 1 Adam Federici; 6 Brynjar Gunnarsson, 24 Ryan Bertrand, 16 Ivar Ingimarsson (capt), 26 Alex Pearce; 4 Kalifa Cisse, 8 Marek Matejovsky (14 Jimmy Kebe half-time), 11 Jobi McAnuff, 25 Gylfi Sigurdsson; 9 Shane Long (23 Grzegorz Rasiak 60), 18 Simon Church. Substitutes (not used): 5 Matt Mills, 19 Hal Robson-Kanu, 20 Jem Karacan, 21 Ben Hamer (gk), 34 Brian Howard.
Booked: Gunnarsson 63, McAnuff 64.
Referee: Simon Hooper (Wiltshire).
Attendance: 12,091 (936 away).