Roberto Pereyra stroked in a penalty here last time out to salvage a point. He was at it again here tonight, decisively affecting the outcome of a second successive home game, again at the same end but this time from closer range, to secure a win that gave everyone the shot in the arm they badly needed.

The goal wasn't as valuable as the one he scored against Arsenal in terms of Premier League points, and how we'd all trade this one 11 minutes from time for three of the finest in the league, but it may do something intangible for confidence levels and help start to build a bit of momentum and put a few smiles back on faces. It was certainly no bad way to warm up for the key game in Wolverhampton on Saturday. A win, however it was achieved, was all that mattered tonight. A few more goals and winning with a bit of panache would have been a bonus.

Another big positive to glean was the return to goal scoring form of Danny Welbeck. This was his first Watford goal, his first since the Europa League tie with Sporting on October 25 and his first on English soil since Arsenal's win over Brentford at the very same stage of this competition a year ago. There is nothing like a goal to make a striker feel better about life, especially after a long injury.

There were a few ghosts to exorcise after Saturday and everyone, the crowd, the players, were a bit tentative after the events at the Etihad. It wasn't a big deal and one press doesn't make a performance, but it was an encouraging sign when Daryl Janmaat charged down Declan John, the Swansea left-back, deep in Swansea territory early on.

There wasn't much to write home about in the period shortly after. Nathaniel Chalobah had a free-kick deflected over and Welbeck thrashed one into the side-netting from an acute angle on the left, but there wasn't really a clear cut chance of note.

It felt like it needed one to go in off someone's knee, someone's backside or even, as it happened, the back of someone's head, Welbeck's header deflecting off his marker and giving Kristoffer Nordfeldt no chance. It was just what everybody needed.

The lead, though, lasted only six minutes in a blow that would have cut Quique Sánchez Flores. He would dearly have loved a clean sheet after watching ten go in in his first two games, something completely anaemic to a coach who prides himself on defensive organisation. While the Head Coach would pick holes in how the backline was breached, even he would have admired the threaded, slide-rule pass from Connor Roberts that sent the overlapping Nathan Dyer flying down the right. He crossed for Sam Surridge who arrived bang on cue to beat Heurelho Gomes. It was all square after 34 minutes.

That gave Swansea a spring in their step and their new-found confidence was summed up when Nordfeldt, the goalkeeper, was dummying Abdoulaye Doucouré in his own area after finding himself in a tight spot. Domingos Quina is never short of a bit of swagger and he performed a neat nutmeg on Matt Grimes, let fly with a rising drive that flew just over the bar and then did Surridge, the goalscorer, up like a kipper.

It was all Swansea for a ten-minute period after the break. Christian Kabasele had to make a magnificent, acrobatic clearance from under his own bar to deny Yan Dhanda and then George Byers almost arrowed one in from distance on his first return these parts.

Sánchez Flores responded by bringing on Tom Cleverley, Ismaïla Sarr and Gerard Deulofeu in the space of 20 minutes and it took the latter less than three minutes to make the decisive intervention. He engineered some space down the left, created half a yard and fizzed the ball across the face for Pereyra to hook in from close range.

From there it was just about seeing it out, locking things down and scraping through to the next round. Nobody cared how it was achieved. It was just about getting the job done.