Bristol City, from English football's second-tier, pulled off a sensation in the League Cup quarter-finals as they knocked out the holders Manchester United 2-1 amid late and wholly improbable drama at their Ashton Gate home on Wednesday.
On one of the great nights in the Championship club's 123-year history, City despatched the Premier League giants amid ecstatic scenes with a winner three minutes into stoppage time from Korey Smith.
City's reward for their famous win was to earn a semi-final tie with runaway Premier League leaders Manchester City while Chelsea, who also defeated Bournemouth 2-1 in a dramatic finish at Stamford Bridge on Wednesday, were later drawn to play Arsenal.
Manchester United manager Jose Mourinho, who saw his chances of winning a fifth League Cup ended, mixed praise for the victorious underdogs with the observation that they were also "lucky".
"They played brilliantly, fought like it was the game of their lives which it probably was," he said on Sky Sports.
"A beautiful day for football. A team from the lower division won. A big day for them."
He had picked a much-changed but strong side with big guns Zlatan Ibrahimovic and Paul Pogba back in the starting lineup but United found it a trying night and could not complain when local hero Joe Bryan put City ahead with a superb 51st-minute strike.
Ibrahimovic, who like Marcus Rashford had hit the post for United in the first half, thundered home a low freekick to restore parity seven minutes later.
Yet City, who are third in the Championship and hunting promotion to the top-flight, kept believing.
They made United the fourth Premier League victims of their fairytale Cup run when, latching on to a fine chipped pass from substitute Matty Taylor, Smith took the ball expertly on his chest and swivelled to fire home left-footed in the final seconds.
"It's an overwhelming feeling of pride, to beat Manchester United is incredible," said City's manager Lee Johnson, whose father Gary was once also a successful manager of the Robins.
"They are a special group. It has been a long time since we had a result like that at Ashton Gate. My dad always says he's the most successful Bristol City manager so I have maybe pushed him close tonight!"
Johnson had bought a special 450 pounds ($601) bottle of wine that he wanted to share with Mourinho after the match -- but instead champagne was the order of the night.
Chelsea looked set to be comfortable winners over struggling Premier League opposition when Willian finished off a fine team move after just 13 minutes but Bournemouth rallied after the break.
Dan Gosling smashed home a deserved equaliser in the final minute but Chelsea launched an attack of their own almost straight from the restart with substitute Alvaro Morata snatching the winner within 40 seconds of Bournemouth's goal.
The late drama at both matches ensured a fascinating last-four draw, with Chelsea playing Arsenal at Stamford Bridge in the first match of the two-legged tie in the week commencing Jan.8.
Bristol City will travel to the Etihad Stadium for their first leg against Manchester City, who are still unbeaten in domestic matches this season, before seeking another famous win at Ashton Gate in the second leg during the week of Jan.22.
Conte hails Chelsea players' grit after Bournemouth win
Chelsea manager Antonio Conte praised his players' determination after the side earned a hard-fought 2-1 win over Bournemouth in their League Cup quarter-final on Wednesday.
A much-changed Chelsea side took the early lead through Willian but Bournemouth midfielder Dan Gosling levelled the score at 1-1 in the 90th minute.
The hosts got the winner through an Alvaro Morata goal less than a minute later and Conte was thrilled to see Chelsea progress to the semi-finals, where they will meet London rivals Arsenal.
"The most important thing is we're in the semi-finals," Conte said after the match. "To reach the semi-final in one of the two cups in England is great for us, especially with a lot (of squad) rotation.
"I had good responses from my players and I hope to continue in this way. Many players had their chances tonight to play from the start and I think I had good responses.
"It's also not simple when you concede a goal in the last minute of the game, so to have this type of reaction shows great character, personality and heart."
Premier League champions Chelsea, who are currently third in the standings, will travel to resurgent Everton on Saturday.