Allardyce's men ran out third-round victors over the non-leaguers by a narrow 1-0 margin at Croft Park, and survived a major scare five minutes from time when substitute Andrew Wright came within inches of cancelling out what proved to be Carlos Villanueva's winner.

But having safely booked a fourth-round trip to Sunderland, the 54-year-old, who rested his entire first team against the Blue Square North side, started to focus on Saturday's trip to Fulham and the business of escaping relegation.

Allardyce said: "We hadn't lost in three matches - now we haven't lost in four. These lads have done well tonight, but I can't see me making too many changes.

"That team that has played so well with such little reward - because they should have had more than five points - will be very much in the frame to play against Fulham."

Allardyce's four games at the helm have now resulted in two wins and two draws, and while the single points his side collected at both Sunderland and at home to Manchester City might have been scant reward for their performances, he was grateful not to be heading back to Ewood Park having to prepare for an FA Cup replay.

Blackburn dominated much of the game, but passed up a series of opportunities to end Blyth's dreams.

Villanueva's 59th-minute free-kick failed to open the floodgates, and had Wright's aim being slightly more true, Spartans' hopes of prolonging their cup run might still have been alive.

Asked if he felt fortunate to have emerged from the late drama unscathed, Allardyce said: "On that chance, yes, but on the rest of the game, no.

"I would say some good defending and some poor finishing from our point of view meant we should have had a good two or three-goal lead by that time, but didn't, so we all had our hearts in our mouths when that one came across."

Blyth boss Harry Dunn was left to reflect on what might have been, as well as the task of dragging his side out of their own relegation troubles.

He admitted Allardyce's decision to rest his big names had given his side a chance, and he applauded them for giving it a real go.

Dunn said: "If Sam had put his first team out, you have got to be realistic, we probably wouldn't have had a hope in hell.

"The main feature from our point of view was not to concede goals because if we had conceded two, we weren't going to score three.

"But at one, you always have a chance and for us to stay in the game as long as we did was great testament to the players."