A superb performance from second-half substitute Claudia Pina proved to be a catalyst for the hosts, as the Catalans went from being 1-0 up with 25 minutes remaining to securing an impressive 4-1 win.

Hannah Hampton had saved an early Alexia Putellas penalty before Ewa Pajor gave Barca the lead ten minutes before the break.

Substitute Pina doubled their advantage, poking home from close range just four minutes after her arrival, but the deficit was halved four minutes later when Sandy Baltimore scored.

The game was finely balanced heading into the final stages but Irene Paredes converted a Pina cross in the 82nd minute and the challenge we face at Stamford Bridge next week was made even tougher in the last minute of normal time when Pina added her second for 4-1.

This was only Sonia Bompastor's second defeat in charge of Chelsea since she joined in the summer, the other a 2-0 loss to Manchester City in the first leg of the Champions League quarter-final.

Our turnaround against City at the Bridge will give the players hope heading into the second leg against Barcelona a week today.

Bompastor stuck with an unchanged XI from the side that delivered the last-minute win over Liverpool at Kingsmeadow that saw us reach the FA Cup final last weekend.

The early exchanges were evenly matched. Both sides were looking for an opening but neither goalkeeper was properly tested.

Penalty save

But after 10 minutes the the referee was called to consult the VAR screen for a potential handball by Nathalie Bjorn following a corner. After viewing the replay, the official awarded a penalty to Barcelona.

Up stepped the experienced Putellas, but her effort was hit down the middle, and Hampton pulled off an incredible reaction stop with her legs to keep the score at 0-0.

Despite their setback, Barcelona continued to try to make their home advantage count in the first half and Hampton was once again called upon to make a save when Aitana Bonmati attempted a shot from range. The stopper was Chelsea's safe hands once again.

After the Chelsea goalkeeper had received treatment on her shoulder for a heavy challenge, Barca found their opening. A defence-splitting pass from Putellas rolled right into the path of Pajor, who found herself one-on-one with the England international and delivered the finish.

As the clock ticked into added time in the first half, Barcelona's Caroline Graham Hansen cut inside and curled a shot just over the bar, but then Chelsea had a chance of their own when Erin Cuthbert was fouled just outside the area and was awarded a free-kick.

Aggie Beever-Jones forced a save out of Cata Coll with a bending effort, and Lucy Bronze just couldn't get her head on a cross at the far post from the resulting corner that was swung in by Baltimore.

With an hour gone, Bompastor switched things up by swapping Beever-Jones and Wieke Kaptein for Catarina Macario and the fit again Guro Reiten.

And while both sides cancelled each other out for the opening 25 minutes of the second half, Barcelona struck again when Ona Batlle played in the recently-introduced Pina who was able to finish from close range.

Deficit reduced

The Blues hit back almost immediately with a Macario pass across the box to Baltimore, who let fly with an angled shot beyond Coll and into the bottom corner.

But Barcelona netted their third on 82 minutes. Pina was involved once more as her dangerous corner found the head of Paredes, who found the back of the net and restored the home side's two-goal advantage.

And Barcelona grabbed a fourth in the final minute of play when Pina scored from close range.

What it means...

The Blues will need to overturn the 4-1 defeat at Stamford Bridge next Sunday if they are to reach the final in Lisbon.

What comes next...

Chelsea return to action in the Women's Super League on Wednesday evening as we face Crystal Palace at Kingsmeadow in a bid to move one step closer to the title.

The teams

Chelsea: Hampton; Bronze, Bjorn (Girma 81), Bright (c), Baltimore; Walsh, Kaptein (Macario 61), Cuthbert; Rytting Kaneryd, Beever-Jones (Reiten 62), Ramirez (Nusken 88)
Chelsea substitutes: Spencer, Cox, Jean-Francois, Charles, Hamano, Lawrence, Girma, Mpome, Brown
Scorers: Baltimore 74
Booked: Ramirez 41, Macario 72

Barcelona: Cata Coll, Paredes, Maria Leon (Engen 45), Paralluelo, Graham Hansen (Pina 66), Putellas, Patri, Bonmati, Pajor, Batlle, Brugts (Rolfo 82)
Barcelona Substitutes: Gemma, Roebuck, Jana, Marta, Pina, Rolfo, Vicky, Engen, Cano, Schertenleib
Scorers: Pajor 35, Pina 70, 90, Paredes 82
Booked: Pina 77

Referee: Katalin Kulcsar

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