Quadruple-chasing Chelsea fell to a heavy defeat in the first leg of their Women's Champions League semi-final with Barcelona.

Ewa Pajor gave Barcelona a first-half lead when she coolly slotted the ball past goalkeeper Hannah Hampton after being played in behind by Alexia Putellas' clever pass.

Substitute Claudia Pina doubled their advantage, poking home from close range midway through the second half.

However, Chelsea had proven to be a threat in spells and responded when wing-back Sandy Baltimore drilled an effort into the far corner to halve the deficit.

That looked set to give Sonia Bompastor's side a real opportunity in the second leg at Stamford Bridge next Sunday (14:00 BST) but Irene Paredes added a third goal for Barcelona late on.

As if Chelsea's evening could not get any worse, Pina rounded off an impressive evening for Barcelona with a fourth in stoppage time.

It is a third straight meeting between the sides at this stage of the competition, with Barcelona coming out on top in the previous two - and they will have enjoyed causing further pain in Spain.

England forward Aggie Beever-Jones came close for the visitors when her curling free-kick was pushed behind by goalkeeper Cata Coll, scrambling low to her left.

That came during a positive spell for Chelsea, who ended the first half on top despite trailing.

They had goalkeeper Hampton to thank for saving a first-half penalty from two-time Ballon d'Or winner Putellas.

Barcelona remain the team to beat in Europe and it was a tough evening for Chelsea, who have a lot of work to do in London.

"It was difficult just to lose the game but also to concede four goals," said manager Bompastor afterwards.

"These games are really difficult because Barcelona are one of, if not the best team in Europe.

"When the result was 2-1, we were not in a really bad situation because there was only one goal in it. But the last 10 minutes were not good enough."

Chelsea captain Millie Bright said during the build-up that they had to take their emotions out of the tie having suffered enough heartache against Barcelona in the past.

In a lively encounter, the visitors did well initially to limit Barcelona's chances and Hampton was tough to beat in a resilient first half.

However, all of that work went out the window in a devastating final 20 minutes as Barcelona showed why they have dominated European football in recent years.

With Chelsea tiring and pushing for an equaliser, Barcelona demonstrated their ruthless streak, piling on the pressure to build a comfortable lead.

That has caused huge damage to manager Bompastor's chances of guiding Chelsea to their first Women's Champions League title in her first season after replacing Emma Hayes.

And it has also threatened to end their hopes of securing a quadruple this season.

It means Chelsea will have to produce one of their greatest performances in the second leg to stand a chance of reaching the final.

Barcelona, meanwhile, are in a strong position to continue their push for a third successive Champions League trophy.

There were spells of Chelsea's performance that showed they could compete but they were not good enough across the 90 minutes and may have paid a heavy price.