The Blues' hopes of securing a first Women's Champions League title were dashed as Barcelona won 2-0 at Stamford Bridge to overturn a 1-0 first-leg deficit and reach the final in Bilbao on 25 May.

Chelsea manager Emma Hayes said: "Barcelona benefited from the worst decision in the history of the Women's Champions League," as the reigning champions came back from their first home defeat in five years at the Estadi Olimpico.

The Spaniards were the better side and Ballon d'Or winner Aitana Bonmati opened the scoring just after the midway point of the first half. Chelsea's task was made that bit harder when Kadeisha Buchanan was sent off after an hour for a second bookable offence although replays suggested she had not even fouled Patri Guijarro.

WIth less than 20 minutes to go, Barcelona were awarded a dubious penalty for Ashlely Lawrence's challlenge on Bonmati, and Fridolina Rolfo converted as the Catalan giants clinched a fourth consecutive trip to the final.

Either PSG or Lyon stand between Barcelona and a third Women's Champions League triumph. The two French sides meet on Sunday with Lyon leading 3-2 after the first leg.

Hayes was obviously frustrated by the decisions made by referee Iuliana Demetrescu that went against her team, saying, "We were on top of the game in the second half. Then when you get a shocking decision like that from the referee, there's nothing you can do about it. It's difficult when you have 11. It's practically impossible when you've got 10."

The Englishwoman, who will soon be moving on to take charge of the United States women's national team, went further with her criticism of the Romanian official and admitted her surprise at her appointment for the game, as reported by AFP. 

She said of Cuthbert's second booking, "Even the Barcelona players said they knew the referee helped them. I didn't think it was a foul, let alone a yellow card. She is known for her leniency in handing out cards, which is reflected in her numbers. It's probably the worst decision in the history of the women's Champions League, in my opinion."

Barcelona head coach Jonatan Giraldez said, "We are very happy. We deserved to win. In the first leg, we were no better than our opponents. Today we created the better chances. The bond between the players is incredible. I am proud of the players. I am very happy to be playing in another final. It's special."

Bonmati, who was named Laureus Sportswoman of the Year at the start of the week, was the best player before opening the scoring in the 25th minute. The home side almost levelled early in the second half but Sjoeke Nusken hit the post before Buchanan's gamechanging red card.