Beattie pen 49, 57
JAMES Beattie scored set-piece goals twice in the space of eight second-half minutes for Sheffield United to send Argyle back to the Westcountry empty handed.
Defeat came four days after a 1-0 win at United's Steel City neighbours, Sheffield Wednesday, and Argyle's weary performance after the break in comparison to their determined display in the opening 45 minutes suggested the traveling may have taken its toll.
The first goal came from the penalty spot after Chris Barker felled Anthony Stokes and Beattie underlined his status as a deadly dead-ball specialist with a curling free-kick to confirm the win for the Blades.
Argyle manager Paul Sturrock made three changes to his team from the Hillsborough success. Krisztián Timár returned to the starting line-up for the first time since mid-September when he was dmissed in the first half of the 2-1 home defeat to Norwich.
Manchester United loan defender Craig Cathcart was the man to make way, having fallen victim to a similar bout of sickness which forced Jamie Mackie and Yoann Folly out of the trip to Sheffield Wednesday.
In another defensive move that suggested Luggy was fearful of the fatigue-factor, Mathias Doumbe stepped in for David McNamee, who only made the starting line-ups for last weekend's defeat to Ipswich and the Hillsborough win after missing the start of the campaign through injury.
Winger Nicolas Marin was also drafted in for his first start since his September loan move from Lorient in France, meaning the slightly more defensive-minded Jim Paterson was dropped to the bench.
The area Luggy decided not to tinker with was up front, where the match-winner at Hillsborough, Steve MacLean, was again paired with Paul Gallagher, as Argyle sought to breach a Blades' defence that had only been beaten once in their last six league games.
The now recovered Mackie and Folly took their places on the bench with young Craig Noone and Simon Walton the unlucky men to dip out from the squad that secured victory in Argyle's first trip to the Steel City.
Former Pilgrim Kevin Blackwell made just one change to his Sheffield United team after their battling 0-0 draw at Bristol City in midweek.
The experienced Gary Speed came into the midfield engine room in place of the suspended Brian Howard. Blackwell also shifted his deck slightly on the bench with Matt Kilgallon returning.
A shaky opening from Marcel Seip almost gifted the Blades a goal after two minutes. The Dutch defender tried an extravagant curling cross with his left peg which, to say the least, didn't work.
Speed picked up the pieces and intelligently fed the ball into the gap vacated by Seip for the sprightly Danny Webber to run on goal. Doumbe just scampered across quickly enough to prevent him from squaring the ball to Beattie and the eventual shot was expertly turned wide by the boot of Romain Larrieu.
The next Pilgrim to attempt a first-time cross was Luke Summerfield, and he executed the delivery superbly; forcing United stalwart Chris Morgan to head clear under pressure from Gallagher.
An intriguing start to the match highlighted what would surely be the two key tussles: the aerial war played out by Timár and Beattie at one end, and the clash between the craft of Gallagher and sheer determination of Morgan.
After losing a couple of headers to Beattie in defence, Timár won the first battle at the other end, getting his head onto a Summerfield corner via a Gallagher flick after a late run to the back post. The header flew narrowly wide but it was decent execution of an obviously pre-rehearsed set-piece.
The Gallagher v Morgan meeting was accompanied by the interesting sub-plot of a vastly improved MacLean buzzing around the experienced Ugo Ehiogu. Early indications suggested the Green pair had the mobility and intelligence to give their direct opponents a difficult afternoon.
At the other end, the Beast of Budapest floored Beattie with a typically robust challenge but, to his credit, the former Southampton striker sprang to his feet like a man relishing the physical test of an afternoon with Timár.
Beattie then had a fair chance to open the scoring after a deep corner evaded everyone and landed at his feet but, despite having time, he rushed a disappointing shot that sliced wide of Larrieu's near post.
An even better chance then fell to Stokes, who, having bamboozled Seip with a clever trick, attempted a low curler that Larrieu did well to turn wide. Speed immediately took the best-chance-wasted mantle with a wild volley from the subsequent corner.
It was a brief flurry from the hosts that didn't detract from an excellent first-half performance of linkage and determination by MacLean, and Timár showed his annoyance at the distraction by nailing with Beattie with another industrial challenge.
Despite Timár's growling, Sheffield United ended the half in the ascendancy with Argyle's backline forced into some, not quite desperate, but definitely, stretched defending.
The second half started with stretched turning swiftly into desperate as Stokes strolled past Timár and into the box. Barker's late attempt to cover the run ended with a cumbersome bundle on the former Sunderland forward.
Referee Scott Mathieson had little option but to award the penalty and Beattie stepped up to fire an unstoppable spot-kick beyond Larrieu and into the top corner.
Recent form suggested Argyle were far more comfortable holding onto a lead than chasing one and the immediate exploitation of the increasing gaps in defence by the now rampant Blades was a big problem for the Greens.
It was a problem Argyle couldn't solve and after Summerfield conceded a free-kick on the edge of the box, Beattie curled in his second of the afternoon with a delicious low drive. Mission improbable had turned into mission impossible.
Luggy immediately responded to the challenge by introducing Rory Fallon for the disappointing Marin and switching to a three-pronged attack with the Kiwi flanked by MacLean and Gallagher.
Unfortunately, the lead galvanized the Blades and Argyle were suddenly coming off second-best in all the 50-50 tackles, although a Summerfield stinger from 30 yards did warm the hands of United's woefully under-employed goalkeeper, Paddy Kenny.
It would be unfair to say Beattie had won his battle with Timár, but he had definitely won his battle with Larrieu, and, at the other end, MacLean and Gallagher, and now Fallon as well, were being comfortably stifled by the United defence.
However, one opportunity to arrest the decline arrived after MacLean got the wrong side of Morgan following a Fallon flick, but he scuffed the shot into the grateful arms of Kenny.
Beattie then missed the chance to score his hat-trick five minutes from time after good work from substitute Billy Sharp but Larrieu did well to parry the low shot.
McNamee and Mackie had joined the rescue party but it was Sheffield United's afternoon and they coasted to victory against the travel and game-weary Greens.
SheffieldUnited (4-3-3):1 Paddy Kenny; 30 Kyle Naughton, 5 Chris Morgan, 34 Ugo Ehiogu, 12 Sun Jihai; 25 Matt Spring, 28 Stephen Quinn, 15 Gary Speed; 10 Danny Webber (2 Greg Halford 86), 9 James Beattie, 8 Anthony Stokes (24 Billy Sharp 65). Substitutes (not used): 6 Matt Kilgallon, 17 Nick Montgomery, 18 Nathan Dyer.
Argyle (4-4-2):1 Romain Larrieu; 13 Mathias Kouo-Doumbe (16 David McNamee 65), 5 Kristián Timár, 19 Marcel Seip, 15 Chris Barker; 23 Nicolas Marin (14 Rory Fallon 58), 2 Karl Duguid, 20 Luke Summerfield, 6 Chris Clark (25 Jamie Mackie 76); 11 Paul Gallagher, 9 Steve MacLean. Substitutes(not used): 3 Jim Paterson, 8 Yoann Folly.
Booked:Doumbe 53, Gallagher 78.
Referee:Scott Mathieson (Cheshire).
Attendance:25,601 (655 away).