Martin O'Neill claims he is not merely the right man for the job but the only one, and now he has a chance to prove it. It is unlikely that Sunderland's manager would have been sacked even if his struggling side had lost to Reading but the Wearsiders' third win in the last 24 Premier League games and a first victory against opponents finishing with 11 men since March undoubtedly offers O'Neill invaluable breathing space.

Forthcoming trips to Manchester United and Southampton followed by home fixtures against Manchester City and Tottenham Hotspur are likely to fully test the strength of Sunderland's latest mini-renaissance but, for the moment at least, they are out of the bottom three. "I'm delighted to have won, it's a real boost," said O'Neill. "There's a sense of relief. Scoring early took a bit of anxiety out of the crowd. Of course there'll be really tough times ahead but we'll try and see it through."

The game had barely begun before Sunderland nudged Reading a fraction closer to a return to the Championship. Their lead derived from a set-piece, Adam Johnson's corner being partly cleared by Adam Federici, who should really have held it. The ball dropped to the much improved James McClean who swept a low, skimming, left-footed half volley inside the near post from just inside the area.

Down in the technical area the tension momentarily disappeared while up in the directors' box Ellis Short, Sunderland's owner, was spotted smiling. Before kick-off Short had visited the press room, speaking warmly of O'Neill and the players, and gently chiding a reporter expressing puzzlement at such patience.

Although Federici partly redeemed himself by capably repelling Sebastian Larsson's stinging shot soon after, his defence looked capable of conceding almost every time Sunderland attacked.

The bad news for O'Neill was that while Reading appeared horribly vulnerable at the back – where Adrian Mariappa laboured at centre half – they were very much better going forward. Indeed with Jay Tabb enjoying himself in central midfield and Nicky Shorey crossing dangerously, Sunderland found themselves frequently struggling for control.

At least O'Neill had Danny Rose on his side. Controversially selected at left-back rather than in central midfield, the versatile, highly talented Tottenham loanee surged forward before crossing towards Steven Fletcher's feet.

Lurking with his back to goal the centre-forward – only playing thanks to a pain-killing injection in an ankle – beat Federici with a neat semi-swivel and backheel flick. It was the Scot's seventh goal of the season. He very nearly extended that tally shortly before half-time but instead headed another Johnson corner tantalisingly wide. Minutes earlier Johnson had almost been scythed down at the thigh by Jobi McAnuff's overexuberant challenge and not surprisingly, Phil Bardsley replaced him after the interval.

Despite the two-goal lead O'Neill, a bundle of nervous energy throughout, never looked entirely comfortable. He may have given a BBC reporter who had the temerity to inquire whether he had succumbed to self doubt short shrift last weekend, but whenever Reading strung a few passes together Sunderland's manager appeared anxiety personified.

Meanwhile, a few feet to his right, Brian McDermott merely seemed to be regretting his failure to come equipped with gloves. As the temperature plunged below freezing and fans began wondering whether they had remembered to put windscreen de-icer in their cars, Reading's manager tugged his coat sleeves down over his hands and ran through a repertoire of increasingly resigned expressions.

It may have been different had Simon Mignolet not produced a wonderful save to divert Shorey's free-kick, but the game drifted increasingly out of Reading's grasp. "We're in the results business and we're not winning games, but the boys are giving me everything," said a sanguine McDermott. "We played some decent stuff. We've got to keep going, keep enjoying ourselves."

His players perked up a little when Rose – and how O'Neil must hope he can reach a deal over his permanent transfer with André Villas-Boas next month – limped off to a standing ovation.

Although the referee was not buying the penalty claim followed Bardsley's perceived foul on McAnuff, Mignolet excelled when saving Noel Hunt's goal-bound header. A shaky cameo from the substitute Titus Bramble followed but Stéphane Sessègnon raised the tone in injury time, bursting through and outmuscling Mariappa before rounding Federici and passing the third goal into an unguarded net.

With a mini-crisis averted O'Neill was left to raise his arms and salute every corner of the crowd.