Emma Hayes called the referees" decision to send off Chelsea defender Kadeisha Buchanan as the "worst in Women"s Champions League history", as her side crashed out to Barcelona at the semi-final stage with a 2-0 defeat. The tie was level at 1-1 from the first leg, with Aitana Bonmatí cancelling out Erin Cuthbert"s strike, but the game at Stamford Bridge turned decisively against Chelsea in the second leg. Buchanan stretched for a loose ball and was judged to have caught Patri Guijarro on the ankle, with referee Iuliana Demetrescu showing the Blues defender a second yellow card. Chelsea were left to hold off the European champions for the final 30 minutes with 10 players.