Coming up against a side who have not tasted victory all season in their own league, many would have expected us to run riot in a London derby which at one time would have been a fairly common fixture but had yet to be played in the Women’s Super League era before today.

It certainly didn’t pan out that way during the first half, though, as we struggled to find any fluency in our attacking play and barely fashioned a chance for the majority of the opening 45 minutes.

That all changed when the fourth official held up the board for stoppage time, as Spence latched onto a knock-down and casually slotted home the opening goal.

Inside the opening minute of the second half we had doubled our lead and this time it came from a rather less familiar source, as Emily Murphy netted her second goal for the club.

The young forward, making her first start, showed good composure to take a long pass in her stride and she finished at the second attempt.

Ten minutes later and we were cruising into the fifth round, this time after Spence doubled her tally for the afternoon by sending the goalkeeper the wrong way from the penalty spot after Charlotte Fleming, another Academy graduate, had been brought down.

With the Blues now in complete control, it looked a case of how many we’d score, but to the visiting side’s credit they held firm until Murphy added another with a smart finish from close range.

Attention now turns to tomorrow’s fifth-round draw, which is the start of a busy week. We face Manchester United in the semi-finals of the Continental League Cup on Wednesday and then we’re back at Kingsmeadow next Sunday for the visit of West Ham United.

Following last Sunday’s thumping 4-1 win over Arsenal, Emma Hayes retained only two members of that starting XI for our game against a side at the bottom of the Championship and without a victory in the second tier this season. Captain Magdalena Eriksson and Sophie Ingle, scorer of a wonder goal last weekend, were the two to keep their place.

That mean Carly Telford was brought in between the sticks, playing behind a back four of Hannah Blundell, Jess Carter, Eriksson and Deanna Cooper. In midfield, Ingle was joined by youngster Fleming, making her second appearance for the senior side following her start at Lewes in the Continental League Cup in November, and Spence, who had taken similar steps towards first-team football 11 years ago this month.

There was no shortage of youthful exuberance and pace up front, either, as the experienced Ramona Bachmann was joined by Jamie-Lee Napier and Murphy, both of whom were making their first start for the club. The latter entered the game full of confidence, having netted on her last appearance against Aston Villa in the Conti Cup.

It was a slow start at the home of VCD Athletic, with a bobbly pitch certainly not aiding the Blues’ usual fluid passing game and Addicks looking to frustrate us in front of a buoyant home crowd. Indeed, there was little cheer for either set of supporters until the 12th minute, when Napier gave us a glimpse of the lightning-quick pace we were told about when she signed from Hibs before Christmas.

The Scot breezed past her marker with the minimum of fuss and clipped a cross into the box which was half-cleared. The ball eventually dropped to Blundell, who had scored at this stage of the competition last term against Everton, but her fierce shot was headed over the bar by a Charlton defender.

Despite plenty of endeavour, we were struggling to find a way through the home defence and their aggressive pressing whenever the ball was played out to our full-backs was giving the crowd plenty of encouragement. It was clear something wasn’t working for Hayes’ side and just before the half-hour mark the players used an injury-enforced stoppage in play to hold a mid-match meeting.

Suddenly, the passing was crisper and the movement sharper. Our first shot on target duly followed and it perhaps should have resulted in a goal. Although Murphy’s first effort was blocked, after being found by a slide-rule pass by Spence, the rebound dropped to Blundell and her centre was directed towards goal by Bachmann, but she couldn’t get enough on it to force it past keeper Katie Startup.

The Swiss star made way for Guro Reiten soon after and having started the game with heavy strapping around her right thigh, it would be reasonable to suggest injury was the cause for her early departure with 10 minutes of the first half remaining.

Just as it looked like the half-time whistle would come with the game still goalless, the Blues made the breakthrough with our best move of the half. After a period of patient build-up play, the ball was clipped into the box towards Fleming, who nodded down and into the path of Spence to open up her body and sidefoot into the far corner.

Having opened our account in first-half stoppage time, it then took less than 60 seconds for our lead to be doubled after the break – and the goal could hardly have been more straightforward. Eriksson clipped a long ball over the top which was brought down superbly by Murphy and although Startup did well to keep out her initial effort, the forward slid in the rebound to score her second goal in as many appearances.

The game was well and truly put to bed before an hour had even been played, as the Blues were given an opportunity from the penalty spot after Fleming was brought down by a defender just as she was about to pull the trigger. Spence stepped up and sent the keeper the wrong way; having struggled for so much of the game, we had now scored three in 12 minutes either side of the interval.

Charlotte Wardlaw was brought on soon after in place of Blundell and there was almost another new addition to the scoresheet as her namesake Fleming ghosted in at the back stick to power a header across goal which Startup superbly palmed away to safety, before denying Napier from our next attack.

There was a lovely moment when Reiten almost scored a complete fluke, as she lofted a hopeful ball up into the air and it was taken by the wind, deceiving the keeper in the process and bouncing off the top of the crossbar. She immediately turned to acknowledge the home supporters behind her, grinning from ear to ear and bursting into laughter along with the fans.

It looked like Charlton would hold us to three, but with a few minutes remaining the influential Reiten was involved once again as she knocked the ball down the line for Cooper to square and Murphy to finish. It capped an excellent performance by the youngster, as she netted her second of the game to mark the end of a dominant second-half showing by the Blues.

After sealing our progress in the FA Cup we face Man United in the Continental League Cup on Wednesday, with a place in the final at stake, and then we’re back at Kingsmeadow on Sunday 2 February for the visit of West Ham United. Click here to buy your tickets now!

Charlton Athletic Startup, Newborough, Coombs, Dorey, Clifford, Woodham (Gardien 55), Estcourt (Griffin 15, Eide 69), Griffiths, Legg, Heuchan, MustakiUnused subs Salgado, EspinosaBooked Newborough 43, Coombs 56

Chelsea (4-3-3) Telford; Blundell (Wardlaw 59), Carter, Eriksson (c), Cooper; Spence, Ingle, Fleming (Bright 90+2), Napier, Murphy, Bachmann (Reiten 36)Unused subs Berger, Andersson, Mjelde, EnglandScorers Spence 45, 57 (pen), Murphy 46, 84

Referee Robert Massey-Ellis

Crowd 844