After scoring within five minutes through Garnacho, the home support at Stamford Bridge may have been expecting a repeat of Wednesday night’s five-goal display against Ajax.
Marc Guiu was the only survivor in the front four from the win against the Dutch giants, with Garnacho, Joao Pedro and Pedro Neto starting in support.
But Garnacho’s solo opener was as good as it got for the Blues, who struggled for creativity despite their apparent wealth of flair in attack.
Back-to-back wins against Liverpool and Nottingham Forest had put Enzo Maresca’s side within three points of second place, but the Argentine’s side did not play like a team with an opportunity to close the gap on leaders Arsenal.
Their lack of threat was summed up by the fact it was Garnacho who was hooked in the 58th minute.
Brazilian Estevao was tasked with injecting some potency to Chelsea’s attack but the teenager’s introduction did little to lift the side.
Liam Delap, who has missed the last two months through injury but returned to training this week, watched from the sidelines as Reece James and Marc Cucurella put enticing crosses into the box.
Without the England Under-21 international, Chelsea lack a goal poacher – particularly when Joao Pedro plays in a more withdrawn role.
The Blues visit bottom-placed Wolves (19:45 GMT) in the EFL Cup on Wednesday, before taking on Spurs in the Premier League next Saturday (17:30 GMT)
