Striker Liam Delap scored his first Chelsea goal as the Blues qualified for the knockout stages of the Club World Cup with a win over ES Tunis.
The 22-year-old scored with a placed shot deep into first half added time to get off the mark after his £30m move from Ipswich earlier this month.
It came just two minutes after defender Tosin Adarabioyo headed in a free-kick from Enzo Fernandez to open the scoring.
Substitute Tyrique George added a late third with practically the last kick of the match in front of 32,967 fans at Lincoln Financial Field.
Manager Enzo Maresca's team selection appeared to be impacted by the extreme temperatures in Philadelphia, which still 'felt like' 36C by the 9pm kick-off because of the humidity.
The Italian made eight changes and rested star forward Cole Palmer, Chelsea's top scorer in the competition Pedro Neto, and record signing Moises Caicedo.
Maresca rang further changes during a flat second half as Chelsea eased away from an improbable upset against their African opponents, who came into the match needing a win to progress at Chelsea's expense.
Victory means Chelsea progress as runners-up in Group D, behind winners Flamengo, to set up a last-16 meeting with Portuguese club Benfica.
Delap proved he can be a threatening option up front, with alternative striking option Nicolas Jackson still suspended for the last-16 match against Benfica following his sending off against Flamengo.
The forward opened his Chelsea account with a stylish goal - a deft first touch, spin and placed shot into the bottom corner just before referee Yaez Falcon Perez blew his half-time whistle.
The England under-21 international had earlier spun into space after Noni Madueke's pass inside and saw a shot saved by goalkeeper Bechir Ben Said.
Midfielder Enzo Fernandez captained the team in the absence of an ill Reece James and set up both goals before being taken off for debutant Andrey Santos in the second half. Mamadou Sarr also made his first appearance for the club.
Several Chelsea players struggled to impress - like Kiernan Dewsbury-Hall, Malo Gusto and Christopher Nkunku - but it was understandable in such difficult conditions after so many changes.
Chelsea dominated possession on a hot evening, having 74% of the ball. They also managed 16 shots to just three - and none on target - from ES Tunis.
Chelsea progress in second place from Group D behind Flamengo to set up a last-16 match with Benfica on Saturday.
ES Tunis join Los Angeles FC in being knocked out of the tournament.