DO you believe in miracles? If you're a Sunderland supporter, you probably believe you've witnessed one.

One month to the day after Gustavo Poyet sat in the White Hart Lane press room to effectively write off his side's chances of Premier League survival, a barnstorming display against West Brom completed the greatest of great escapes with one game to spare.

A miracle? In footballing terms, it's the equivalent of turning water into wine. While you're in the middle of a drought.

No one saw this coming. Not the supporters, who trudged disconsolately out of White Hart Lane, and then watched their side lose at home to Everton five days later. Not Sunderland's players, who looked to have given up the ghost as they conceded three goals in 13 hapless minutes against Spurs. And certainly not Poyet, who carried the air of a broken man as he looked into the abyss and saw no way back.

His assessment of the Tottenham defeat was unusually blunt, but in truth, his words barely caused an eyebrow to raise.

The reason for that was simple – seven points adrift of safety with seven games remaining, Sunderland did need a miracle. And at the time, you would have been hard pressed to find anyone willing to gamble on them pulling it off.

So how has the turnaround occurred? A multitude of reasons, some planned, some less so. But the combined effect is that Sunderland head into Sunday's final game with Swansea with their survival assured.

If you're looking for one killer reason why they suddenly find themselves on the right side of the relegation cut-off point, the return and rehabilitation of Connor Wickham is surely the main factor.

Cast into the Championship wilderness as Sunderland's fifth-choice striker at the end of February, Wickham would almost certainly have been finishing the season with Leeds United had Steven Fletcher not picked up an injury that ruled him out of the final two months of the campaign.

With Jozy Altidore proving utterly ineffective, and Ignacio Scocco way off the pace required in the Premier League, Poyet had run out of places to turn. So he rang Elland Road, thrust Wickham into his starting line-up at Anfield and, after a run of five goals in three matches, the rest is history.

A player Paolo Di Canio once derided for paying too much attention to his T-shirts has fashioned the most unlikely of revivals.

There was undoubtedly an element of serendipity to Wickham's renaissance, and that is not the only time that things have fallen in Sunderland's favour in the second half of the season.

Had Stoke City been able to put together an acceptable package on transfer-deadline day, Lee Cattermole would almost certainly have left the Stadium of Light. Had Liam Bridcutt not suffered a personal problem, Cattermole would probably have been consigned to the bench in the last month. Instead, the two factors have combined to make the Teessider one of the spearheads of Sunderland's remarkable renaissance.

Similarly, the unavailability of Ki Sung-Yueng has effectively forced Poyet to pair Jack Colback, who opened the scoring last night as he converted Marcos Alonso's cross, with Seb Larsson, who provided the delicate chipped pass that enabled Fabio Borini to net shortly after the half-hour mark, at the heart of midfield.

The pair's partnership, which blends an abundance of steel with a degree of skill that is sometimes underplayed, has enabled Sunderland to be resolute enough to compete with the likes of Manchester City and Chelsea, while still being positive enough to score four goals against those two teams. Would they have been anything like as effective with a below-par Ki still in the side? That is not to say that Poyet does not deserve credit for the parts of the recovery that have been planned though.

Having sensibly abandoned a brief flirtation with a five-man defence during matches against Liverpool, West Ham and Spurs, the Sunderland boss has gone back to basics in order to turn his side around.

Four at the back, three committed ball winners at the heart of midfield, two genuine wingers playing out wide and an old-fashioned centre-forward up front. It's not rocket science, but it's taken the best part of a season for the Black Cats to end up with what suddenly looks routine.

Similarly, while Poyet's January acquisition of Santiago Vergini looked ill-advised at the time, the Argentinian has proved a more than capable replacement for Phil Bardsley in recent games. With an option in place to sign the defender permanently this summer, Sunderland supporters might well be seeing a fair bit more of him in the future.

Poyet has also proved adept at changing things in recent weeks, with last night's decision to introduce Bridcutt and Altidore for Adam Johnson and Wickham shoring Sunderland up at a crucial stage when West Brom's post half-time flurry was threatening to turn the game in their favour.

Most importantly of all, the South American has cultivated a strong team spirit from the wreckage he was bequeathed by Di Canio. When the pressure was at its most intense, Sunderland's players pulled themselves together and hauled themselves back from the brink.

Their strength of purpose is all the more remarkable given that so many of them will be leaving Wearside as either free agents or returning loanees this summer. Thanks to their efforts, those that remain will be playing Premier League football again next season.