• Big Sam glad to escape drop zone

Roberts added the third four minutes from time, just after Nicky Butt had been sent off for a second bookable offence after clattering into David Dunn.

With Middlesbrough hammered at West Brom and Tottenham not playing until Sunday it meant Rovers moved up to 17th place, out of the bottom three on goal difference.

If ever a match was more about the result than the performance it was this one.

The first 25 minutes of a disappointing game passed without major incident as neither side was able to enjoy a decent spell of possession or pressure.

Newcastle striker Andy Carroll nodded Damien Duff's sixth-minute cross tamely wide, Keith Andrews cleared off the line from Carroll's looping header at a 13th-minute corner and Michael Owen bobbled a shot across Robinson's goal.

When Blackburn got the ball their delivery was poor, with Tugay and Brett Emerton both guilty of wasting possession.

Morten Gamst Pedersen had one decent break from the centre of midfield but when it came to picking out the run of McCarthy he failed miserably.

The ball spent more time in the air than at players' feet and right-back Andre Ooijer and Tugay both blazed long-range shots well over as a lack of inspiration led to desperation.

What the watching England coach Fabio Capello and Republic of Ireland boss Giovanni Trapattoni made of it is anyone's guess.

Things picked up slightly when Chris Samba's 36th-minute header from Pedersen's inswinging corner bouncing a couple of feet past Shay Given's right-hand post.

However, at the other end Butt should have at least hit the target from eight yards having been played in by Duff on the right but he poked his shot wide, and Carroll also hooked well over from a corner.

Late on in the half Blackburn lost Samba to an eye injury after Carroll accidentally caught him with an elbow, meaning a reshuffle with midfielder Dunn coming on.

Emerton slotted in at right-back and Ooijer moved into the centre of defence.

Five minutes into the second half Duff put Owen through but when he crossed to the far post Charles N'Zogbia fired high over the crossbar.

N'Zogbia then fouled Andrews on the edge of the Newcastle penalty area but McCarthy's driven shot around the wall was superbly tipped on to the left-hand post by the diving Given.

Tugay was replaced by Vince Grella in the 59th minute as Allardyce sought to inject more drive into the midfield and within two minutes Rovers were ahead.

Emerton's hanging right-wing cross was destined for McCarthy at the far post until Jose Enrique sent the striker tumbling to the floor.

Referee Rob Styles pointed to the spot and the South Africa international picked himself up to fire past Given.

It was his fourth goal in as many matches having been restored to the starting line-up when Allardyce replaced the sacked Paul Ince in mid-December.

Rovers were immediately lifted and Roberts made it 2-0 five minutes later when Robinson's long punt downfield was helped on by Pedersen and McCarthy smashed home his third in five matches.

McCarthy immediately departed to a standing ovation as Allardyce sent on Santa Cruz.

The Blackburn fans seemed to be in two minds how to react. The Paraguayan's arrival was greeted by a chorus of boos but less than a minute later they were chanting his name.

Newcastle's frustrations boiled over in the 83rd minute when Butt clattered into Dunn and was sent off for a second yellow card, having been booked 10 minutes earlier.

The former England midfielder reacted by blasting the ball into the crowd before taking a slow walk off the pitch and down the tunnel.

Roberts added the third four minutes from time when he stabbed home Pedersen's cross from close range.