Liam Delap scored his first Chelsea goal as the Premier League side reached the last 16 of the Club World Cup with a 3-0 win over Esperance Tunis.
The former Ipswich forward struck just moments after defender Tosin Adarabioyo had opened the scoring in first-half stoppage time of their final Group D game in Philadelphia.
Tyrique George scored a third in time added on at the end of the game after Chelsea had a penalty awarded for handball overturned by VAR.
The result means the Londoners will now face Benfica - surprise winners of Group C ahead of Bayern Munich - in the next round in Charlotte on Saturday.
It was an occasion when Delap began paying back his £30 million fee.
With Nicolas Jackson suspended, the 22-year-old was one of just three players to retain his place as manager Enzo Maresca stuck to his plan to rotate his side on what was a hot and sticky night in Pennsylvania, with the temperature still 33C when the game kicked off at 9pm local time.
His goal - coming in a quickfire double, both created by Enzo Fernandez - put the game beyond doubt before the interval.
Chelsea, with a superior goal difference to Esperance, knew a draw would be sufficient to secure the runners-up spot in the group behind Flamengo.
That put the onus on Esperance but, despite some attacking vibrancy, they lacked the quality up front.
Delap created the first chance of the night when he skipped around two challenges but his shot was comfortably saved by Bechir Ben Said.
Kiernan Dewsbury-Hall got in a header from a Malo Gusto cross but it looked to be going wide before Yassine Meriah headed clear. Josh Acheampong forced Ben Said to save from distance but the flag was raised before Delap could get to the rebound.
Another good move led to Fernandez blasting wide but Chelsea finally took control with their quickfire double in first-half stoppage time.
Adarabioyo opened the scoring with a well-placed header across goal after rising to meet a Fernandez free-kick.
Fernandez was again the provider as the Londoners doubled their lead moments later. This time he chipped forward for Delap and the striker turned brilliantly to beat one defender and flick past another before rolling the ball past a statuesque Ben Said.
Nukunku appealed for a penalty after going down early in the second half but nothing was given before Noni Madueke sent a shot narrowly wide.
Chelsea were awarded a spot-kick when an Andrey Santos effort from distance struck the arm of Meriah. It seemed a harsh decision but there was a long delay, with Christopher Nkunku stood over the ball waiting to take it, before the referee was called over the monitor and changed the decision.
Chelsea finally got the third goal their superiority deserved when substitute George's shot squirmed through Ben Said's grasp.
Delap: Hopefully it is the first of many
"Obviously it is a really happy feeling and hopefully it is the first of many," Delap told the club's website, chelseafc.com.
"I spoke to Enzo [Fernandez] and he told me when he gets the ball to just run. It was a great pass and luckily it went in.
"I love playing football and to play for such a good team is a great feeling.
"We had to win to get through and we are all happy we are into the next stage."
Maresca: Important to bounce back and win
"It was important to bounce back and win," said Maresca. "Now we can start to think about the next one.
"It was very important to be patient and then when we found the goal it became a bit more open.
"We are happy for all the players, especially for the ones who have gone a long time without minutes.
"From 32 teams now we are in the last 16. Hopefully we can go to the last eight."
The Blues will now face Benfica - surprise winners of Group C, ahead of Bayern Munich - in the next round in Charlotte on Saturday.
