Nemanja Matic's first-half header was enough for Chelsea to record a first victory of Champions League Group G, but it should have been so much more comfortable than a 1-0 win at Sporting Lisbon.
The Estadio Jose Alvalade, where Blues boss Jose Mourinho spent 18 months from 1992 as assistant to Sir Bobby Robson, was vibrant on Sporting's first home clash among Europe's elite in five years.
In arguably the toughest assignment of the group, Chelsea, who opened with 1-1 draw at home to Schalke, were looking to end Sporting's 16-match unbeaten home run in continental competition and should have been 2-0 up inside the opening 22 minutes.
Diego Costa, selected despite his fragile hamstrings, erred in a one on one as Rui Patricio saved after two minutes and 20 minutes later Andre Schurrle missed a straightforward chance.
It was one of a number of opportunities spurned by the German as it appeared the Premier League's top scorers were having an off night in front of goal.
That was until Matic, booed on account of his spell with Sporting's rivals Benfica, headed Chelsea into a 34th-minute lead from Cesc Fabregas' free-kick.
Sporting appealed in vain for a penalty when Gary Cahill blocked a first-half shot, but that was as good as it got for the hosts.
Patricio - congratulated at the end by Mourinho - denied Oscar and Nani, the on loan Manchester United winger, could only find the side-netting for Sporting, who never troubled Thibaut Courtois, even in a finale when they pressed for an equaliser which never came.
Chelsea's domestic dominance has yet to transfer into Europe and the Blues now twice play Slovenia's Maribor, before a trip to Schalke and a home clash with Sporting.
First up is the Premier League leaders' clash at home to Arsenal on Sunday.
While Sporting's home record was formidable, Chelsea's had a strong record of one defeat in nine games against Portuguese opposition.
That was on Mourinho's first return to Porto in 2004 when the Blues were already through in the group.
On Mourinho's first return to his native Portugal since guiding Chelsea to a last-16 draw at Porto in February 2007, Costa started up front, as promised.
Costa scored his eighth goal in six Premier League games against Aston Villa, but was unable to notch his first European goal for Chelsea after being played in by Oscar.
The Spain striker curved his run to stay onside and beat a leaden-footed Sporting defence, but his languid finish was stopped by the feet of Patricio.
Schurrle returned to the starting line-up despite his wastefulness against Bolton last Wednesday and he again floundered in front of goal against a disorganised Sporting defence.
He mis-controlled Eden Hazard's through ball and was then unable to round Patricio as the goalkeeper spread himself well.
Sporting barely threatened as Courtois held Islam Slimani's header from Jonathan Silva's left-wing cross.
Chelsea broke quickly and Schurrle, again, leapt to head Hazard's cross at Patricio before the German forced the goalkeeper to save from the edge of the area.
Schurrle's third chance in the space of as many minutes was the most simple, but he scuffed Hazard's cross wide with the goal gaping.
Matic did not pass up the opportunity presented to him when, unmarked, he met Fabregas' set-piece at the back post and looped his header over Patricio.
Chelsea were in control, but there was a moment of alarm when Adrien Silva had a shot blocked by Cahill, with the vocal locals appealing for a penalty.
It was an illustration of how little Sporting threatened, with William Carvalho firing a tame 25-yard shot straight at Courtois soon afterwards.
The best and worst of Nani was on display when he led a counter-attack, but hit a blank when he flicked the ball into space behind him, with no team-mate present.
Oscar shot straight at legs of Patricio and Nani into the side-netting at the other end before Schurrle was replaced by Willian.
Chelsea looked to hit their hosts on the counter-attack and Costa was felled cynically by Mauricio as he bore down on goal.
The Sporting defender received a yellow card, required treatment after being run over by Costa, and had to go off.
John Obi Mikel, on for Oscar, blasted over and Costa fired into the side-netting from an acute angle as Chelsea played mainly on the break.
Still a second was elusive, but so was a Sporting shot to test Courtois.
Patricio reacted swiftly to deny Costa a shooting chance before Mohamed Salah, on for Hazard, was unable to reach Luis' dangerous cross.
Chelsea were left clinging to their single-goal advantage as the Egypt winger was denied by Patricio, with Nani shooting just over and substitute Fredy Montero heading wide as Sporting twice went close, but not close enough, to an equaliser.
Source: PA
