Sketchy stuff, but not every masterpiece is vivid from the first draft. It is only a year since Aaron Ramsey made his full debut for Cardiff City, in the same round of the FA Cup, and saw Chasetown take an early lead. It finished 3-1 that day, and it was an identical story here, plucky opposition ultimately failing to bridge a gulf in class. Only this time, in the absence of Cesc Fabregas, Ramsey found himself orchestrating a midfield eligible to emulate Cardiff by going all the way to Wembley.
Whether measured by their present frailties or enduring strengths, this tournament remains a bespoke fit for Arsenal. To those who perceive a lack of fortitude in their team, its staccato demands are more suitable than the unremitting challenge of the Premier League.
To those, equally, who consider Arsène Wenger custodian of not just another generation of meteors but also some of the most wholesome values of the game itself, there is an obvious contiguity between their fortunes and those of the sport's most romantic competition. Both have had their difficulties, in trying to stem the corrosive tides of the modern game, but the 7,000 Argyle fans were by no means the only Pilgrims present.
At least they were determined to enjoy themselves, which is more than can be said of their hosts in the first half. Wenger had promised to take nothing for granted, and rested only Manuel Almunia and Emmanuel Adebayor, in whose respective absences Robin van Persie became the club's fourth captain of the season, and was joined up front by Niklas Bendtner.
But while the latter had switched his pink boots for a lime-green pair, they seemed to set a rather bilious tone. The Dane was having one of those hapless afternoons of his, with that propensity to manoeuvre intelligently into position only to tangle his feet once the ball arrives.
He did manage one fine diving header as half-time approached, narrowly wide, in common with efforts from Van Persie and Emmanuel Eboué, while Romain Larrieu had proved equal to shots from Ramsey and Eboué. Plymouth had meanwhile caused Lucasz Fabianski several twitchy moments, not least in tipping over a deft, curling shot from Paul Gallagher.
Arsenal were guilty of too many miscues, too many hesitations. Withinfive minutes of the resumption, however, they were two up. Van Persiewas integral to both goals, stooping to head Samir Nasri's corner into the roof of the net and then firing a low ball across goal, bundled home by David Gray under pressure from Bendtner. However, they promptly allowed Plymouth back in, Gray at once atoning for his blunder by picking out Karl Duguid 15 yards out.
Arsenal never lost their composure, nor the initiative, creating several chances – Bendtner skimming the bar and Nasri's lob cleared off the line – before Van Persie was put through by Nasri and beat Larrieu at the second attempt. Nasri's blocked shot also looped on to the bar and Ramsey was denied by the keeper at full stretch.
"Had we not been focused and completely up for it, we would not have gone through today," Wenger said. "The gap between the Championship and the Premier League has been reduced, the results today prove that."
Plymouth's manager, Paul Sturrock, said: "If someone had told me that we'd be chasing the game seven minutes from the end, I'd have bitten their hand off."
Referee: Mike Jones
Man of the match: Van Persie
Match rating: 6/10