Bristol City manager Lee Johnson said his side "looked like the Premier League side" during Wednesday's 3-1 Carabao Cup win over Manchester United.
Korey Smith's stoppage-time strike secured a stunning 2-1 victory, as the Championship promotion challengers joined Manchester City, Chelsea and Arsenal in the last four.
It is the fourth time the Championship side have beaten a Premier League team in this season's competition and the first time holders United have lost a League Cup game under Jose Mourinho.
Joe Bryan gave City a 51st-minute lead but Zlatan Ibrahimovic equalised shortly afterwards. Then, just when extra-time beckoned, Smith was set free by Matty Taylor and delivered the goods.
"I thought at times tonight we looked like the Premier League side," a jubilant Johnson told Sky Sports.
"The way we passed and moved and the speed on the counter attack. Our goalkeeper had to make two or three fantastic saves but that was always going to happen.
"I don't think many fans will be turning up for work in the morning - they'll be on the cider. Even the scenes at the end with the pitch invasion - you don't want to see it, but I'm sure everyone understands the passion that went with the result."
