Chilean midfielder Carlos Villanueva saved Blackburn boss Sam Allardyce further misery in the north-east as Blyth's latest FA Cup fairytale very nearly lived on.
Villanueva curled home a superb 59th-minute free-kick to finally break Spartans' stubborn resistance on a night when Allardyce's squad players were given a real test in Northumberland.
Indeed, had substitute Andrew Wright's 85th-minute shot been directed six inches more to his right, he and his team-mates would have been heading for Ewood Park and a replay their bravery so richly deserved.
A crowd of 3,445 at Croft Park was on tenterhooks until the final whistle as the majority dared to believe a repeat of their club's famous march to the fifth round of the competition in 1978 was a possibility.
But in the end, it was the English Premier League side which booked a fourth-round trip to Sunderland - its third visit to the Stadium of Light this season - by the narrowest of margins.
However, a team made up of students, roofers, electrical engineers and physiotherapists did themselves proud on a night when the FA Cup once again provided an intriguing contest.
With so many Newcastle fans among the Blyth squad and supporters, Allardyce was never likely to be afforded a warm welcome to Croft Park, and that extended to his players on the pitch as his team, featuring 11 changes, dominated but struggled to kill of the non-league side's brave resistance.
Indeed, while Spartans keeper Mark Bell was comfortably the busier of the two, it was opposite number Mark Bunn who had cause to look on with the greatest concern when he found himself all at sea 26 minutes into a compelling contest.
The home side had not threatened the Blackburn goal at all until Bunn, for reasons best known to himself, came from his line to confront a posse of players converging on a loose ball and was beaten to it by Aaron Mokoena.
The defender's mis-hit clearance arrived invitingly at the feet of Jed Dalton, the man whose last-gasp strike against Bournemouth in the last round had booked his side its big night.
But with Bunn scrambling desperately back towards his line, he missed the target from distance and the men from the top flight breathed a huge sigh of relief.
They had enjoyed the better of what had gone before with midfielder Keith Treacy forcing a good 11th-minute save from Bell, but his clean sheet was in danger on several more occasions before referee Andre Marriner signalled the end of the first 45 minutes.
Rovers had the ball in the net 12 minutes before the break when the lively Matt Derbyshire finished acrobatically, via a deflection, after latching on to a looping ball, but an offside flag quickly halted his celebrations.
But the visitors almost took the lead legally six minutes later when Vince Grella, making just his fifth appearance for the club he joined from Torino during the summer, sent in a firm volley which thumped into defender Richard Pell's chest on the line and was hacked away.
Allardyce knew there was face-saving to be done after the break, while opposite number Harry Dunn could not have asked for much more from his Blue Square North battlers.
There was a real sense of expectation inside the packed ground as the second half got under way with Rovers struggling to make their greater pedigree count.
However, Spartans