A close range Luke Summerfield goal shortly into the second half secured a win for the visitors at St. Mary's.
The first half was all one way traffic for Saints who looked the sharper and more creative of the two sides, as they restricted Argyle who failed to register a single shot in the opening 45 minutes.
However, a flying start from Peter Reid's men in the second period, appeared to catch the hosts cold, and the St. Mary's faithful were left stunned when a ball across the area was pounced upon by midfielder Summerfield, who was able to prod home through the legs of Kelvin Davis from six yards out to send the Green army at that end into raptures.
Despite a brief spell where they were on the backfoot in the game, Saints soon resumed control but even the introduction of Adam Lallana couldn't force a goal. The winger linked up with former Plymouth man Jason Puncheon on numerous occasions to good effect, even though an equaliser never came.
Saints: Davis, Butterfield, Jaidi, Fonte, Harding (Lallana 65), Puncheon (Holmes 90), Schneiderlin, Hammond, Dickson, Connolly, Barnard. Subs (not used): Bialkowski, Wotton, Mills, Seaborne, Chamberlain.
Plymouth: Button, N'Gala, Arnason (Johnson 46), Bhasera, Molyneux, Summerfield (Clark 81), Fletcher, Timar, Peterlin, Fallon, MacLean (Patterson 75). Subs (not used): Larrieu, Duguid, Mason, Noone.
Referee: Mr. J. Moss (West Yorkshire)
Attendance: 21,727 (including 1,864 away)
Puncheon and Morgan Schneiderlin returned to the starting eleven after injuries whilst Lallana was fit enough to take a place amongst the substitutes. There was no room for last season's top scorer Rickie Lambert, however as he continued to recover from a groin strain.
Saints took to the field in their special 125th anniversary year kit for the first time with the smart white shirt and shorts combination contrasting to Argyle's traditional green strip.
David Connolly kicked the first ball of the new season as the hosts quickly set about their task attacking the Northam End.
Two early corners from the boot of Dan Harding maintained the pressure on the visitors as Alan Pardew's side moved forward at every opportunity inside the opening five minutes with winger Puncheon seeing plenty of the ball on the right hand side.
The first chance of note however, came from the left flank as Ryan Dickson supplied a fine cross into the area which Lee Barnard headed wide from six yards out.
As the game started to settle down Saints continued to be bright on the ball and assured at the back with Jose Fonte and Radhi Jaidi looking largely untroubled by Argyle's attacking threat.
On 26 Schneiderlin lined up his first sight of goal as he struck a firm shot from outside of the area, but his effort flew wide of David Button's right post.
Skipper Dean Hammond went even close just a couple of minutes later as he connected to Dickson's cross, but his header from eight yards missed the target.
Another smart move ten minutes before the break ended with Danny Butterfield almost inadvertently giving Saints the lead as his cross shot from the right looped up and over Button's crossbar.
Puncheon delivered another warning from a set piece when his free kick was whipped in at the near post which 'keeper Button spilt before pulling into his grasp.
The last chance of the half arrived as the rain began to fall and it was the unusual sight of Fonte whipping in a powerful cross from the left that created a chance for defensive partner Jaidi to head at goal, but the Tunisian couldn't direct the ball towards the net, but the hosts remained lively as the first 45 minutes came to a close.
Half Time: Saints 0-0 Plymouth
Plymouth replaced Kari Arnason with Reda Johnson in defence at the start of the second period after Arnason suffered a knock in the first half in a collision with Barnard.
And the visitors flew out of the traps as within two minutes they took the lead. MacLean's endeavour on the left created the space inside the area and Luke SUMMERFIELD got the better of Harding before sliding the ball through Davis' legs from close range.
Bondz N'Gala was the first player to go into the referee's notebook for a lunge on Dickson which took half the turf with him, which between them Davis and Harding re-laid.
Anton Peterlin fired wide from distance with Argyle almost unrecognisable from the team of the first half as they started to turn the screw on Saints' backline.
After the hour mark Adam Lallana was introduced in place of Harding to add fresh impetus to the attack. Dickson dropped back into the left back slot vacated by Harding.
Timar's foul on Barnard gave Puncheon an opportunity to strike at goal, but his free-kick again found the arms of Button.
Lallana and Puncehon linked up for the first time on 70 and nearly instantly reaped the rewards after some neat link up on the edge of the box, however Barnard was flagged offside as the latter tried to play the striker in on goal.
Puncheon struck a sweet strike over the top in the next move as Saints started to find their feet.
Lallana, now roaming around the middle of the park combined well with Connolly before firing in a shot which looked in all the way before it was deflected out of play for a corner.
With quarter of an hour left on the clock Argyle replaced MacLean with Rory Patterson in attack. Five minutes later the Greens took off goalscorer Summerfield with Chris Clark coming on in his place.
Saints regained some of their creativeness inside the last ten minutes, and introduced Lee Holmes in place of Puncheon as three minutes were then added on for stoppages.
A flurry of late advances arrived from the hosts, including a corner which Davis came up for, but Plymouth held out to secure the three points and inflict an opening day defeat on Saints.
Full Time: Saints 0-1 Plymouth
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