Chelsea fought back from two goals down to beat Leeds 6-3 as Cole Palmer and Danny Welbeck rescued the Blues in a League Cup third-round classic on Wednesday.
Xabi Alonso's side were in danger of crashing out following Tarik Muharemovic's first-half opener and a Brenden Aaronson goal soon after the interval at Stamford Bridge.
But Alonso sent on England forward Palmer, along with Morgan Rogers, Pedro Neto and Reece James, at half-time and the decision inspired Chelsea's stirring escape act.
Palmer struck twice to haul Chelsea level and Neto put them ahead before Welbeck made it four.
Dominic Calvert-Lewin got one back for Leeds, but Valentin Barco and Welbeck netted to ensure Chelsea moved into the fourth round in style.
Rogers was a key catalyst with three assists and the England midfielder, signed from Aston Villa in the close-season, paid tribute to Alonso's influence.
"It's so enjoyable to play with high calibre players that are here. I'm enjoying my football, trying to be free, and showing what I'm about," Rogers said.
"Playing with a smile and playing free. Good things are happening at the moment, so it's nice. It's a really enjoyable team to play in."
Palmer, a close friend of Rogers since their time in the Manchester City academy, has been revitalised by Alonso after a poor season last term.
"I'm enjoying it. All the attacking players, it's a lot different for us. I think we still have a bit to go, but we are getting results which is the main thing," Palmer said.
Underlining the value of the bond between Palmer and Rogers, on and off the pitch, Alonso said: "For sure, it's so important. To have a great chemistry between them.
"They enjoy assisting together. It's important for the team."
Losing 2-1 at Premier League champions Arsenal on Sunday had ended Alonso's three-game winning start to his reign.
But the Chelsea boss got back on track with the kind of chaotic victory that has defined his brief spell in charge.
Chelsea have scored 16 goals in Alonso's first five matches to showcase their attacking talent.
But they have conceded 10 to prove the defensive issues that plagued them last season have not gone away since Alonso's arrival.
Despite spending £349 million ($472 million) during the transfer window, Chelsea ended the Arsenal game with James and Malo Gusto -- two players who are usually right-backs -- operating in central midfield.
Alonso fielded another untested alignment in the midfield engine room as teenage debut Reggie Watson lined up alongside Argentine youngster Barco.
The 16-year-old Watson -- the fourth youngest player in Chelsea's history -- is the son of Ben Watson, who scored Wigan's FA Cup final winner against Manchester City in 2013.
Alonso's decision to make nine changes was in danger of backfiring when Leeds went in front from a 23rd-minute corner.
Chelsea goal spree
Harry Wilson's delivery to the far post caught Chelsea flat-footed and Bosnia defender Muharemovic powered a header past Mike Penders for his first Leeds goal.
Leeds seemed unfazed by the introduction of Chelsea's stars at the interval and they struck again in the 48th minute.
Ethan Ampadu's cross was flicked on by Lukas Nmecha and Aaronson finished with aplomb.
But Chelsea earned a crucial lifeline five minutes later when Daniel James's soft challenge on Pep Chavarria was deemed worthy of a penalty that Palmer stroked home.
Just two minutes later, Chelsea were level when Palmer's shot trickled past Leeds' debutant goalkeeper Michael Zetterer.
Suddenly, Chelsea were rampant and Neto curled their third goal beyond Zetterer from 20 yards in the 60th minute.
Alonso's men made it four goals in the space of just 12 minutes as Welbeck turned and smashed a powerful strike past Zetterer's weak attempted save.
Calvert-Lewin reduced the deficit in the 75th minute with a clinical finish from Noah Okafor's pass.
But Barco swept into the empty net after Zetterer made a hash of Rogers's cross in the 80th minute.
And Welbeck rounded off the goal spree in stoppage time with a cushioned header from Barco's shot.
League Cup holders Manchester City and Premier League champions Arsenal play their third-round ties next week against Norwich and Ipswich respectively.
Liverpool, who host Tottenham, and Manchester United, who welcome Brighton to Old Trafford, are also in action next week.
Newcastle, Crystal Palace, Bournemouth, Sunderland and Bradford all advanced to the fourth round on Tuesday.
