Chelsea gave themselves plenty of work to do at Stamford Bridge after substitute Claudia Pina’s brace inspired holders Barcelona to a 4-1 victory in the first leg of their Champions League semi-final in Spain.

Ewa Pajor opened the scoring for the hosts in the 35th minute at the Johan Cruyff Stadium after Blues keeper Hannah Hampton had saved a ninth-minute penalty.

Pina scored her first with 20 minutes remaining in the second half, then Sandy Baltimore clawed one back for Chelsea – and restored some optimism – four minutes later.

But the hosts were not finished, and handed Sonia Bompastor’s quadruple-chasing side their biggest defeat in 17 months with an 82nd-minute goal from Irene Paredes before Pina struck again on the stroke of full-time.

Barcelona broke into Chelsea’s penalty area early on and a shot from Patricia Guijarro deflected dangerously off Nathalie Bjorn before Hampton was able to smother it.

Caroline Graham Hansen had a deflected effort roll wide before Hampton fumbled a save from Paredes’ attempt from the resulting corner – which VAR then revealed had caught the arm of Bjorn before it made its way to the Chelsea keeper.

A penalty was awarded and Alexia Putellas stepped up but was denied by Hampton, who read it correctly and dived to her left to make the stop.

The hosts maintained their considerable possession advantage by the halfway point in the first period, with Chelsea doing well to stave off pressure. Hampton comfortably saved Aitana Bonmati’s low effort, then plucked a cross from the air.

But Barcelona top-scorer Pajor then got the hosts in front, facilitated by a reverse pass from Putellas to play through the Poland captain, who found the far corner with a composed finish.

Graham Hansen watched an effort fly just past the top corner in first-half stoppage time, when Aggie Beever-Jones finally called Cata Coll into action and former Barcelona defender Lucy Bronze could not connect with the resulting corner from Sandy Baltimore.

Bompastor made her first changes as the hour mark approached, bringing on Guro Reiten and Catarina Macario for Beever-Jones and Wieke Kaptein.

Barcelona keeper Coll then came out to punch away Johanna Rytting Kaneryd’s cross before Putellas had an effort saved, and there were worrying scenes for Chelsea when Erin Cuthbert appeared to sustain a knee issue but carried on.

Pina registered her second in the 70th minute, four minutes after she was introduced, putting the finishing touch on Ona Batlle’s excellent delivery from the right.

Baltimore’s reply came less than four minutes later, Macario this time the one to provide her team-mate with a fine pass for the France international to direct into the bottom corner from the edge of the area.

There was a good save by Hampton to deny Pina before Chelsea’s million-dollar defender Naomi Girma came on to make her Champions League debut.

Paredes restored Barcelona’s two-goal advantage from an inswinging corner with eight minutes remaining, beating Bronze to the ball and nodding home.

Pina then made it four for Barcelona, latching onto a lovely back-heel from Putellas and bagging her brace with a deflected effort off Millie Bright.