Ahead of this last-16 tie against one of Spain’s top sides, Emma Hayes had said she was looking forward to seeing how advanced her side were going into the business end of the season. It’s fair to say her players gave her an emphatic answer.

Everything looked to be going against us when Atletico’s first foray into Blues territory resulted in a penalty kick, awarded for a foul by Ingle on Rasheedat Ajibade that also earned the Welsh international a red card.

However, Berger stepped up to produce an excellent save to deny Deyna Castellanos, and then it was a case of keeping the visitors at bay and making the most of whatever chances came our way.

The first part of that equation was achieved thanks to a professional defensive display – and the second part owed much to the attacking excellence flowing through the side.

Having got in at half-time level, we began the second half brightly and our reward came when the referee pointed to the spot for the second time in the match, this time for a clumsy foul on Sam Kerr. Up stepped Mjelde to slot a penalty past Hedvig Lindahl, her former team-mate and a legendary former Blue returning to Kingsmeadow for the first time, and put us in front.

Five minutes later, the lead was doubled when Kirby – who had hit the post moments earlier – side-footed a low finish beyond Lindahl’s despairing dive to make it 2-0 and give us a clear advantage.

There was still more drama to come, though, as Berger brought down Ludmila to give Atletico a second opportunity from the penalty spot. Remarkably, she guessed right for the second time in the game, this time to deny Merel Van Dongen, to maintain our lead.

The odds were stacked against us after Ingle’s early dismissal, but this is a special side who have a happy knack of finding solutions, whatever the situation. There’s still work to be done in the second leg next Wednesday, but we’ll be big favourites to get the job done and continue our quest for a maiden Champions League crown.

This was the Blues’ first action since the middle of February, when we won at Bristol City, and the starting line-up showed only one change from that fixture. Hayes revealed prior to kick-off that captain Magdalena Eriksson picked up a knock during an in-house training match last week, which meant our skipper was the only player to drop out of the side, to be replaced by Melanie Leupolz.

With the German midfielder slotting into her usual role in the middle of the park, alongside Ji So-Yun, Ingle dropped in at centre-half, as part of a back four that also included Mjelde, Millie Bright and Jonna Andersson, lining up in front of goalkeeper Berger. There was no shortage of attacking talent on the pitch, as Kirby, Pernille Harder, Bethany England and Kerr all started.

Three of those forwards played their part in what could have been a dream start inside the first 20 seconds, as Bright’s long ball was flicked on first by Kerr and then England, into the path of Harder to smash a shot that didn’t miss the target by much.

Bright has never been shy of pinging a pass from deep and clearly she’d found her range early on, this time hitting a diagonal that gave Ji an even better opportunity to open the scoring. Just as with the chance two minutes earlier, the South Korean was unable to test former Blues legend Hedvig Lindahl in the Atletico Madrid goal, as she sent her effort wide of the far post.

It had been a really positive start by Hayes’ side and another well-worked move led to a fierce strike by Harder that Lindahl brilliantly tipped over the bar, but suddenly the whole complexion of the game was about to turn on one counter-attack.

A raking pass from deep sent Ajibade in behind the Blues back-line and she was bearing down on goal and preparing to shoot when Ingle caught her from behind, leaving referee Tess Olofsson with a huge decision. The Swedish official pointed to the spot and immediately reached for her pocket to show Ingle a red card. With more than 75 minutes of the game to be played, it was a massive moment in the tie.

Castellanos confidently placed the ball down on the spot, with only Berger to beat from 12 yards, but our German keeper got down low to her right to keep the shot out, to the delight of her team-mates and those of a Blues persuasion on the touchline. They knew just how important that save could be.

With Ingle now off the field, Mjelde moved across to centre-half – and the Norwegian, lest we forget, has plenty of experience of that role from earlier in her career – and England was the unfortunate player to be substituted so that Niamh Charles could come off the bench and slot in at right-back.

Despite our numerical disadvantage, we looked comfortable enough, as our reshuffled defence settled quickly. The big difference, however, was at the other end of the pitch, with our attacking threat blunted as the emphasis understandably shifted to a more defensive outlook.

After the action-packed opening to the contest, the remainder of the half played out with few noteworthy moments in either penalty area. The Blues adapted superbly to having a player less and kept Atleti at arm’s length, with Berger largely a spectator and, if anything, we looked the more threatening side. Had Ji been a little more precise with a pass through to Kirby, and the same could be said of a cheeky shot from outside the box by Harder, we could have found ourselves with more than just a clean sheet to hang on to after the break.

Just as in the first half, we began the second 45 minutes brightly and within 40 seconds of the restart we had a great opportunity to go in front. This time Kirby was the creator, sliding a pass through for Kerr in the inside-right channel, but our No20 could only find the side-netting with her finish.

A couple of long-range strikes from Ji meant it was a busy start to the second half for Lindahl, but soon our former keeper was about to face her biggest test of the night as the Blues were awarded a penalty of our own. It came from a wonderful pass from deep by Leupolz, which found Kerr the wrong side of Tounkara and the defender clumsily went into the back of her to concede a spot-kick.

Mjelde and Lindahl were team-mates for more than two years, so the pressure was on the Norwegian. Although the Swedish keeper guessed the right way, Mjelde’s penalty was hit firmly and accurately into the top-right corner to give us a priceless advantage.

It was, in truth, nothing less than we had deserved for our positive start to the second half and suddenly we were brimming with confidence. Kirby embarked on a barnstorming run that saw her stride clear of the Atletico Madrid midfield, before skipping inside a defender and then sliding a left-footed finish that agonisingly came back from the post.

Super Fran didn’t let her head drop, though, and another chance presented itself to her moments later. This time it was on her trusted right peg, as Kerr’s low pass found her just inside the box and she made no mistake with a low finish that Lindahl could only help on its way into the back of the net. In the space of five minutes the tie had been turned on its head as two of our most experienced players delivered when it mattered most.

Ji made way for Erin Cuthbert soon after, having run her heart out, and then our second goalscorer was also replaced to be replaced by Guro Reiten. Within moments of the Norwegian’s introduction, however, the game took another twist as Berger came racing out of her goal and caught Ludmila to give Atletico their second penalty of the game. This time it was Van Dongen who stepped up to take it but, incredibly, Berger guessed right once again to produce another magnificent save.

In the rush for the ball that followed, Berger took a whack to the head, but fortunately she was able to continue – fittingly, too, as at the full-time whistle her team-mates rushed to celebrate with her following two crucial interventions in what had been a barnstorming opener to this tie.

The second leg takes place next Wednesday in the neutral venue of Monza, due to the Spanish government’s restrictions on travellers entering the country from the UK. Kick-off is at the earlier time of 12.30pm. Before that, we’re back in WSL action with a trip to West Ham United on Sunday.

Chelsea (4-diamond-2) Berger; Mjelde, Bright (c), Ingle, Andersson; Leupolz; Kirby (Reiten 78), Ji (Cuthbert 69); Harder; England (Charles 19), KerrUnused subs Musovic, Orman, Blundell, Carter, Fleming, Spence, FoxScorers Mjelde (pen) 58, Kirby 64Booked Ji 56, Kerr 90+1Sent off Ingle 12

Atletico Madrid (4-4-2) Lindahl; Aleixandri, Tounkara, Van Dongen, Strom; Ajibade (Knaak 75), Santos, Meseguer (c), Duggan (Laurent 75); Ludmila, Castellanos (Sampedro 88)Unused subs Peyraud-Magnin, Kazadi, Bernabe, García, Nkout, Iglesias De La CruzBooked Castellanos 45Missed penalties Castellanos 13, Van Dongen 80

Referee Tess Olofsson (Sweden)