LONDON, you have been warned. Sunderland are back at Wembley – and this time it means something. If Jack Ross’ side win the play-off final on Bank Holiday weekend, Trafalgar Square could be a sea of red-and-white for a month.

While the Checkatrade Trophy final was an enjoyable day out, this month’s return trip down Wembley Way, secured by last night’s gritty goalless draw at Fratton Park, comes with the carrot of a potential place in the Championship. After two years of unremitting darkness, Sunderland can finally see the light.

They booked their place against either Charlton Athletic or Doncaster Rovers with a performance of commendable maturity, shrugging off a hostile crowd and a Portsmouth side adept in the arts of play-acting to successfully defend the one-goal lead that had been secured by Chris Maguire’s strike last Saturday night.

Jon McLaughlin made three excellent saves, the pick of which saw him keep out Gareth Evans’ close-range header before the interval, but this was not a case of Sunderland’s players having to mount a desperate rearguard action in the face of incessant Pompey pressure.

Instead, Jack Ross’ side were disciplined in defence and well-organised in midfield, constantly closing down their opponents to deny Portsmouth’s play-makers any time or space in possession.

Whereas Pompey’s midfielders had gained the upper hand in the second half of the Checkatrade final, they were rendered utterly ineffective in both legs of this semi-final. Ross deserves a huge amount of credit for that, along with the indefatigable Lee Cattermole, who covered every blade of grass last night in order to drive his side to victory. Having missed the crucial penalty in March, it would be fitting if Cattermole was to play a starring role in this month’s Wembley final.

He was excellent last night, along with both Sunderland full-backs, who prevented Portsmouth from being able to hurl balls into the box, and the two centre-halves, who marked Ollie Hawkins out of the game for the second time in a week. On the rare occasion Pompey did find any space in the final third, McLaughlin came to the Black Cats’ rescue.

As a result, the feared siege never really came. This was always going to be a test of Sunderland’s mettle, but they passed it with flying colours. Fratton Park was a cacophony of noise at kick-off, with the Pompey chimes ringing out from stands that bounced to a Premier League beat as recently as 2010. Like the Black Cats, Portsmouth can justifiably claim that a place in League One is beneath them. Hence the frantic desire to get out of the division this month.

The game was also played against a backdrop of simmering tensions between the two teams that had been evident in the closing stages of their league game on Wearside in April and threatened to boil over in the second half of last weekend’s first leg at the Stadium of Light.

This was the fifth meeting between Sunderland and Portsmouth this term, and familiarity appears to have bred contempt. Gareth Evans was booked after four minutes for clattering into Cattermole close to the centre-circle. Tom Naylor followed him into referee Peter Bankes’ notebook seven minutes later for throwing the ball at Chris Maguire’s head. It was that kind of night.

Calm heads were required, and to that end, Jack Ross’ decision to restore Grant Leadbitter to the starting line-up was an astute one. Leadbitter has seen it all before when it comes to promotion battles, having made a major contribution to Middlesbrough’s ascent to the Premier League under Aitor Karanka, and his steadying influence alongside Cattermole enabled Sunderland to draw the sting from Portsmouth’s frenetic start.

The hosts dominated possession from the outset, but there was a franticness to their play that prevented them from threatening the Sunderland goal. Tom Flanagan and Alim Ozturk dealt with Hawkins’ aerial threat, while Luke O’Nien’s defensive diligence ensured he was not troubled by the pacey Viv Solomon-Otabor, who was surprisingly preferred to Jamal Lowe, who had been so effective against Sunderland at Wembley.

Evans blazed over the bar midway through the first half, but it was five minutes before the interval before McLaughlin was seriously tested. Thankfully, when he was, the Black Cats goalkeeper was able to prevent what looked a certain Pompey goal.

Hawkins nodded Lee Brown’s cross across the face of goal, affording Evans a free header six yards out. He met the ball reasonably well, but an onrushing McLaughlin blocked his close-range effort with his legs.

Sunderland’s Scottish shot-stopper was called into action again seven minutes after the break, with Hawkins climbing highest to meet another cross from Brown, and again he was up to the task, tipping the ball over the crossbar. McLaughlin was recruited to address a long-standing problem with Sunderland’s goalkeeping department, and has consistently chipped in important saves throughout the campaign.

Craig MacGillivray was less involved at the other end, although Pompey’s shot-stopper had to be alert in the second minute when Leadbitter drilled in a strike from distance.

Aside from that, Sunderland didn’t really threaten before the interval, although the recalled Maguire might well have added to his winner on Saturday night had he kept his feet when he broke clear ten minutes before the break. He chipped the ball past MacGillivray as he galloped on to Leadbitter’s through ball, but slipped as he was attempting to round the keeper, enabling Christian Burgess to hack clear.

Bryan Oviedo hammered a rising drive over the bar at the start of the second half, but Sunderland spent the majority of the second period containing Pompey’s threat.

Both Cattermole and Leadbitter were once again instrumental to their success, with the former treading a perfect line between focused aggression and composure. Snapping into tackles in the central area, he never once allowed his passions to get the better of him.

With Charlie Wyke retaining possession effectively as a lone striker, Sunderland always had an out ball, and while Portsmouth tried to turn the screw after the interval, they struggled to gain a foothold in their opponents’ final third.

With Hawkins failing to make an impact, Kenny Jackett turned to James Vaughan, and the former Sunderland striker almost made an immediate impact. He had only been on the field for two minutes when he met Brett Pitman’s cross with a downward header, but McLaughlin made his third crucial save of the night with his feet.