An incredible second-half comeback including six goals in 41 minutes saw Chelsea finally blow away Leeds 6-3 in one of the all-time Carabao Cup classics at Stamford Bridge.
The Blues found themselves two goals behind when Brenden Aaronson struck after 47 minutes to add to Tarik Muharemovic's opener, and it appeared Xabi Alonso's first real cup test would end in disappointment - despite the half-time introduction of Cole Palmer, Morgan Rogers, Pedro Neto and Reece James.
A Palmer penalty turned the game on its head suddenly after Pep Chavarria was caught by Dan James, but it was Rogers who inspired the comeback, making four of Chelsea's six goals.
Three of those assists - for Palmer's second, Neto's strike and the first of two for Danny Welbeck - came as Chelsea netted three times more in 12 minutes, including Welbeck's fourth which should have given them breathing space when he fired through Michael Zetterer's legs.
Not for the first time in Alonso's short reign however, chaos once again reigned over control as Leeds continued to create chances before Dominic Calvert-Lewin pulled them back to within a goal with 15 minutes to go.
It was still uncertain that Chelsea had finally sealed their progress when Valentin Barco blasted them 5-3 up from close range from another Rogers assist, but they could finally rest easy in added time - and extinguish Leeds' commendable never-say-die attitude - when Welbeck nodded Barco's wildly mishit effort beyond Zetterer.
If there was ever a goal to sum up a game, this was it. Alonso was handed another clear indication of where his side remain lacking - but for now, chaos isn't serving them too badly.
Leeds head coach Daniel Farke on Your Site:
"We played with confidence, there was not even a chance for them, then the referee decided to give a penalty.
"Nobody was asking for it, all of a sudden their players came into the game. The momentum was on their side. Situations can change the whole momentum of the game."
Chelsea manager Xabi Alonso on Your Site:
"There was so many changes. There was a risk. Things weren't going the way we planned, so we had to change. I take responsibility with the first half. The crowd were great, with the atmosphere [pushing the players on].
"I like that [the substitutes] were ready before the game. They knew they weren't starting and they were ready to make an impact.
"When you put together a team that hardly plays together, it is difficult to play at this level when [Leeds] are intense."
Player of the match Cole Palmer on Your Site:
"You can see I'm enjoying it. Me and Morgan Rogers, Joao Pedro, the attacking players.
"Not to say the defenders aren't - but it's a lot different.
"We've still got a bit to go, but we're getting results and that's the main thing."
21: DOUBLE SAVE! Mike Penders is called into action twice in a matter of seconds to deny Muharemovic and Aaronson with a superb double save.
23: GOAL! From the second of two subsequent corners, Muharemovic rises highest at the back post to nod the opener back inside the opposite corner.
46: SUBS! Palmer, Rogers, James and Neto are introduced for Estevao, Jamie Gittens, Malo Gusto and 16-year-old debutant Reggie Watson.
47: GOAL! In spite of those changes, Aaronson doubles Leeds' advantage following excellent work down the right from Ethan Ampadu.
51: PENALTY TO CHELSEA! The Blues are handed a lifeline when Dan James is penalised for catching Pep Chavarria's standing leg in the Leeds box.
53: GOAL! Palmer strikes from 12 yards to give Chelsea hope.
55: GOAL! Palmer pulls Chelsea level by using Jaka Bijol as a shield to bend the ball beyond Zetterer to level.
60: GOAL! Neto completes a stunning turnaround when he finds the bottom corner following a sweeping attacking move, though again Zetterer should do better.
65: GOAL! Welbeck makes it 4-2 by turning away from two defenders and shooting through Zetterer's legs.
75: GOAL! Substitute Calvert-Lewin powers home to give Leeds hope from Noah Okafor's cross.
80: GOAL! Barco slams home a fifth at the back post from Rogers' low ball through the box.
90+4: GOAL! Welbeck adds a bizarre sixth, nodding home Barco's wildly mishit shot to finally seal victory.
