But the visitors, who are fighting for their lives at the other end of the table, simply refused to lie down and ensured the outcome was in doubt right until the final whistle.
"If you were a neutral, then you would have been on the edge of your seat," said Blackwell. "But it's not so good when you are in my position.
"We were coasting and then we started to do things that we shouldn't have been doing.
"But the boys showed really good guts to come through and you're going to need that at this stage - plenty of them in fact.
"It's coming to the business end now and I don't think you are going to see too much pretty flowing football from anyone from now on.
"The most important thing is getting the points and we did exactly that."
United immediately seized control of proceedings when the impressive Camara slotted home after seven minutes.
Lee Williamson pounced on Chris Morgan's headed clearance before feeding Mark Yeates who in turn sent the Senegalese scampering through for his fourth goal of the season.
Ward netted his first of the afternoon with an emphatic finish 28 minutes later following Toni Kallio's cross.
With his side looking dead and buried, Argyle manager Paul Mariner made two changes for the start of the second-half and both substitutes - Yannick Bolasie and Joe Mason - repaid his faith with simple efforts.
But not before Ward had completed his brace after some awful Argyle defending.
Richard Cresswell took advantage of a David Stockdale howler - the Argyle 'keeper blissfully unaware of the former Stoke marksman's presence as he attempted to take a clearance - to restore United's two-goal lead but Jamie Mackie pounced during the closing stages to set up a nervous finish.
Mariner said: "David has just had one of those once in a career moments hasn't he?
"What can you say to the kid?
"There's not a lot you can say because he probably feels like shooting himself.
"But we'd conceded three poor goals before that so I don't blame him.
"However, we showed plenty of bottle to come back and that's what we're going to need between now and the end.
"We need to go on a good run.
"It's as simple as that."
Source: Team Talk
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