Chelsea 0-2 Barcelona (1-2 agg): Blues dealt Champions League heartbreak as controversial semi-final second-leg defeat knocks them OUT - with Aitana Bonmati and Fridolina Rolfo on target

The problem with playing the best team in the world over two legs is that you need to produce a perfect performance twice. Chelsea managed it in Barcelona, but were undone at Stamford Bridge. The small margins went against them. 

A deflection which helped Aitana Bonmati level the tie in the first half. The crossbar and post, which saved Barcelona on multiple occasions. But most importantly, Chelsea were left rueing two controversial officiating decisions that swung the balance of this second leg in Barca's favour.

The first saw Kadeisha Buchanan wrongly sent off for a second bookable offence on the hour mark, leaving Chelsea to play with 10. The second saw Aitana Bonmati, who had brought Barca level on aggregate in the first half, win a questionable penalty - which Fridolina Rolfo converted.

It was not the Stamford Bridge swansong Emma Hayes deserved and there will be no fairytale ending in Bilbao next month. Chelsea may still win the Women's Super League title, but they could also finish the season without silverware.

Football is not always fair, and the way Chelsea lost this game felt unjust. Hayes appeared to utter the words 'I feel robbed' at full-time. To have pushed Barca so close will be of little comfort, but both Hayes and her players can be proud.

After inflicting a first home defeat in five years on the Catalans last week, Chelsea knew their opponents would throw everything at them in the opening stages of this second leg. 

After weathering the storm for 25 minutes, the Blues' resistance was broken when Bonmati's shot from the edge of the box deflected off Kadeisha Buchanan and into the bottom right corner. 

Chelsea's response to going behind was positive but they saw three good chances to equalise go begging. First, Macario forced Cata Coll into a fine save with a half-volley from the edge of the box. 

Then Melanie Leupolz hit the bar at the back-post when it was easier to score. Chelsea should have equalised again when Barca played themselves into trouble as Irene Parades' backpass to Coll was intercepted by Sjoeke Nusken. 

The midfielder's cut-back evaded James but dropped to Johanna Rytting Kaneryd. She laid the ball back to Erin Cuthbert but her effort flew over the bar.

Another huge chance fell Chelsea's way early in the second half when Ashley Lawrence was played in by James. The full back picked out Nusken in the box, but the midfielder's shot hit the outside of the far post and bounced wide.

Then came the first controversial moment. 

Buchanan had been booked for an earlier foul and when she challenged for the ball with Patri Guijarro, referee Iuliana Demetrescu gave a free-kick to Barca and brandished a second yellow card for the Chelsea defender. 

Replays showed Buchanan had won the ball cleanly, but because it was a second yellow card rather than a straight red, VAR could not review the incident. Buchanan had to walk and Chelsea had to play with 10.

The Blues had done well to keep Barca at bay, but in the 75th minute another decision went against them. Bonmati was played in down the left and fell to the ground in the box while under pressure from Lawrence and Jess Carter. 

The referee pointed to the spot. It was harsh, with replays indicating Bonmati had initiated the contact, but it was the type of decision that VAR does not overturn.

Hayes threw on Millie Bright as a makeshift striker in the hope of keeping the game alive, but Barca's player advantage meant Chelsea could not break their opponents down.