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 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.
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.
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.
But 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 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.