Cesar Azpilicueta marked his first Chelsea appearance since returning from the World Cup with the decisive penalty against Inter Milan as the Blues ran out 5-4 winners after a 1-1 draw.
Pedro put Chelsea ahead in the International Champions Cup tie in Nice after Alvaro Morata had forced a save.
Chelsea peppered Inter’s goal with 10 shots in the opening half without adding to their lead.
Inter forced a penalty shootout after Roberto Gagliardini equalised.
Spain defender Azpilicueta, who did not play a game in Russia, was one of a number of players making their first Chelsea appearance since returning from the World Cup.
Willy Caballero (Argentina), Antonio Rudiger (Germany), Victor Moses (Nigeria) and Andreas Christensen (Denmark) also came on against Inter.
However, France World Cup winners Olivier Giroud and N’Golo Kante were absent, as were Belgium duo Eden Hazard and Thibaut Courtois.
Other absentees included Gary Cahill and Willian.
Chelsea started with the same side that began the 1-0 friendly win over Perth Glory in Australia on Monday, with Cesc Fabregas named as captain.
Seventeen-year-olds Ethan Ampadu and Callum Hudson-Odoi again got the nod from new boss Maurizio Sarri, along with 18-year-old Polish keeper Marcin Bulka, as new 38-year-old signing Robert Green watched from the bench.
More frustration for Morata
Chelsea should have been out of sight by half-time before fading after the break.
Even before Pedro’s eighth-minute goal, Ross Barkley had forced Samir Handanovic to save with his leg before Alvaro Morata had a header ruled out for offside.
Morata found the net 11 times in the Premier League last season but ended the campaign without a goal in his final six top-flight games.
The 25-year-old Spain forward did well to keep the ball in play leading up to Pedro’s goal but was unable to maintain his promising start to the match and was replaced after 65 minutes.
Jorginho forced a fine one-handed save from distance on his second appearance since joining from Napoli.
The Italy midfielder calmly scored Chelsea’s first penalty during the shootout with Danny Drinkwater, Moses and Tammy Abraham also netting from the spot.
Caballero used his legs to keep out Inter’s Milan Skriniar before Azpilicueta’s winning kick.
Chelsea continue their International Champions Cup campaign against Arsenal in Dublin on Wednesday (20:05 BST) before next Sunday’s Community Shield against Manchester City at Wembley (15:00).
Sarri’s side round off their pre-season preparations at Stamford Bridge against Lyon on 7 August (20:05) – four days before their opening Premier League game at Huddersfield on 11 August (15:00).