Bristol City beat Premier League club Crystal Palace to reach the third round of the League Cup for the first time in 10 years.
After a lacklustre first half, City's Jay Emmanuel-Thomas curled in a right-footed strike to open the scoring.
Midfielder Scott Wagstaff then calmly slotted home from Bobby Reid's centre to double the League One side's lead.
Owen Garvan fired in a sensational volley for Palace in injury time, but it was a mere consolation.
It means Crystal Palace's 34-year wait for a victory at Ashton Gate continues, but, perhaps more worrying for Bristol-born boss Ian Holloway, they remain without a win this season following league defeats by Tottenham and Stoke.
And the Eagles, who made 11 changes from the weekend defeat at Britannia Stadium, struggled to find their stride against an impressive City side.
Emmanuel-Thomas drilled towards goal to force 35-year-old debutant Neil Alexander into an early save.
Stephen Dobbie responded with some neat work in the box but saw his shot blocked, while Elliot Grandin headed over the bar following a rare Palace attack.
Former Arsenal youngster Emmanuel-Thomas, who joined City in the summer after an unsuccessful spell with Ipswich, proved his pedigree with the opening goal - bending his shot passed Alexander after receiving a precise cut-back from Sam Baldock.
It was soon 2-0 when Reid swept the ball across the box to Wagstaff, who calmly struck low into the net.
Crystal Palace began to test the home defence late on, substitute Kyle De Silva's low drive gave keeper Elliot Parish a challenge on his debut.
Although Garvey's wonder strike from 20 yards out provided some last-minute nerves, City saw it through.
Bristol City manager Sean O'Driscoll:
"It was a night of positives; we've saved our best performances for this cup.
"You want your cup form to have an influence in terms of confidence. We don't want the cup form to hinder the league form and we've lost two players, 19 and 20, through fatigue tonight as they aren't used to playing Saturday and then Tuesday in games of this intensity.
"We are skating on thin ice with the squad. They changed all 11 players; we are not able to do that."
Crystal Palace manager Ian Holloway:
"It is obvious, isn't it? We need some wide men and we need to address the goals and that is what we'll be doing.
"The main thing for me is that we've lost two of our main players, who were really important for us last year, in Glenn Murray with his injury and Wilf (Zaha, who has joined Manchester United).
"You add the new lad I bought in Jerome Thomas and Yannick Bolasie to that and we aren't quite the same. It makes a huge difference.
"It certainly will be a busy rest of the week. I don't know where it will go and how we will end up, but we will get some players - you can see we need them."