I watched Sunderland's tense win over Portsmouth and here's four key things I noticed

Sunderland moved to within striking distance of the Championship automatic promotion places with a 1-0 win over Portsmouth.

Phil Smith was there reporting for The Echo and here are his key conclusions...

A TRICKY AFTERNOON - BUT AN ABSOLUTELY DESERVED WIN

This was without a trickier game for Sunderland than many had anticipated and with the visitors reduced to ten, the final stages were more nerve-wracking than they probably needed to be. Sunderland were a little fortunate that when Terry Devlin whipped a wicked cross into the box with not long left to play, Colby Bishop's knockdown did not fall to a fellow team mate.

Sunderland also lived dangerously for large spells of the first half, losing the ball in dangerous areas and had the visitors found a little more composure and quality, they would have equalised. If John Mousinho's decision to play a high line and press despite the pace of Wilson Isidor and Eliezer Mayenda in behind looked reckless when the two combined early on, then it was almost vindicated thereafter. They have a very poor away record this season but on another day, they'd have nicked something from this one.

On a number of levels, however, a sense of perspective is required. If Sunderland looked shattered in the closing stages, struggling to make the right decisions and to apply pressure on the ball, then that's because they are. A very small group of players has had to play the vast majority of the minutes in five games across fifteen games, and to take ten points in that time is a very solid return.

And though at times there was real jeopardy in this game, we shouldn't lose sight of the fact that Sunderland were clearly deserved winners on balance of play. They generated an XG of 2.30 to Portsmouth's 0.36, had 24 shots to Portsmouth's six, of which eight were on target and 14 were taken from inside the box. They had three big chances according to Fotmob and only some inspired defending from substitute Rob Atkinson kept Pompey in the game ahead of what was almost a grandstand finish on their part.

All things told, it's a decent sign that Sunderland can look short of their best and still create this volume of chances in a game. They've reached the end of a very demanding period within two points of the top two and eleven points clear of seventh. That's an impressive achievement.

WILSON ISIDOR IS THE ROSS STEWART HEIR WE DIDN'T SEE COMING

Afterwards, Mousinho rued that his side had erred and given an opportunity to a player he described as one of best centre forwards in the division. After last season's struggles, Sunderland fans might have struggled to believe they'd have a striker on eight goals at the start of January and drawing such praise from opposition bosses.

The last time that happened on a regular basis was in the Ross Stewart era, when managers would queue up to laud his all-round athleticism after games. This was another game in which Isidor's movement and pace was the difference between the two sides. Though the switch to a 4-4-2 does mean Sunderland lose some control of midfield, having Eliezer Mayenda occupying the opposition backline as revitalised Isidor and he is causing teams so many problems with his ability to cover so much ground in behind the defence. This was also yet another one-touch finish, highlighting how clinical he can be when the opportunities arrive.

There are genuinely strong similarities with Stewart in his playing style and coincidentally, they both arrived on Wearside having played a lot of football on the left wing for their previous clubs. They also happen to share an idol in Thierry Henry.

Recommending Isidor was an inspired decision on Le Bris's part, and a very good piece of recruitment by Sunderland.

FORMATION CHANGE MIGHT WELL BE TEMPORARY

Against Sheffield United we saw the upside of playing with two strikers and again in the early stages here, but this was also a game that more broadly probably underlined why Le Bris prefers to have an additional body in midfield.

Without a more defensive midfielder Sunderland looked more vulnerable to both long balls and the counter attack than they have at home for much of this season, and it's much easier for them to control possession deep in opposition territory when they can build their triangles through Chris Rigg and Jobe Bellingham.

Le Bris has found a very valuable Plan B in recent weeks, one he can deploy on occasions and particularly in the latter stages of games when the extra pace in the forward line can cause tired defenders all sorts of problems. For the most part, though, we can likely expect him to return to his tried and tested formula when key players return from injury.

DENNIS CIRKIN'S PROMISING CAMEO

Sunderland were forced into a substitution at half time with Aji Alese feeling unwell. With Dennis Cirkin ready and waiting, Le Bris felt there was no need to take any risks with Alese and made the change.

Cirkin immediately offered a welcome burst of energy down the left flank, overlapping Adil Aouchiche and creating some really good opportunities. Though he has not played badly by any stretch of the imagination, there's no doubt that Cirkin has not looked quite as explosive going forward since returning from wrist surgery. This was his most dynamic display since that injury and bodes very well heading into the rest of the promotion race.