Ross Barkley missed a late penalty as Chelsea succumbed to a 1-0 home defeat to Valencia in Frank Lampard’s first Champions League match as manager.
Rodrigo’s volley put the Spanish side ahead before the Blues won a contentious late penalty after Daniel Wass was adjudged to have handled in the area.
But substitute Barkley stepped up and hit the crossbar with his effort to miss the chance to salvage a draw and fall to a disappointing defeat.
Lampard made just one change to his line-up with Kurt Zouma replacing the injured Antonio Rudiger after an encouraging 5-2 victory against Wolves on Saturday.
But the Blues suffered an early blow when Mason Mount’s Champions League debut came to a premature end after suffering an ankle injury just nine minutes into the match .
The 20-year-old suffered a heavy knock to his ankle after a high challenge from Valencia’s Francis Coquelin, who was shown a yellow card for the tackle from referee Cuneyt Cakir.
The Chelsea midfielder initially tried to run off the knock but soon realised he couldn’t continue and limped off to a standing ovation at Stamford Bridge.
After the injury, the Blues failed to recover their momentum as Valencia grew into the game and Rodrigo should have put the visitors ahead only to head straight at his compatriot Kepa.
Despite two chances for Willian before and after the break, the visitors went ahead after a clever free-kick routine. Dani Parejo lifted it over into Rodrigo’s path and the Spain international volleyed past Kepa Arrizabalaga.
Chelsea had the chance to level late on after VAR controversially awarded the hosts a penalty when Wass handled in the area. After a three-minute delay, referee Cuneyt Cakir pointed to the spot but substitute Barkley, grabbing the ball confidently, hit the bar with his spot-kick.
That was the closest Chelsea came to equalising as the Blues began their Champions League return with defeat.