Ipswich manager Mick McCarthy admitted his side carried out a 'mugging' after snatching a 1-0 win at the iPro Stadium which sentenced Derby to a second home defeat in four days.
Former Derby striker Luke Varney scored early in the second half and Ipswich defended strongly to hang on, although Rams substitute Nick Blackman wasted a great chance to level in stoppage time.
Ipswich had not lost at Derby since 2006 but that record was under threat as the hosts dominated without finding a way past Bartosz Bialkowski, who did well to keep out a low Matej Vydra shot in the ninth minute.
Bialkowski also denied James Wilson before the break and Derby were continuing to push in the second half only for Varney to stun them in the 53rd minute, firing in a 20-yard shot that Scott Carson could only palm inside his right-hand post.
Will Hughes did his best to save Derby and shot inches wide before setting up Blackman in the third minute of added time, only for the striker to fire straight at Bialkowski.
McCarthy said: "We've mugged them to be fair, they were better than us, they dominated the first half and for 10 minutes we were hanging on.
"But it's all about the stuff I preach to the players and sometimes supporters don't like it when I talk about being resilient and tough, hard working and putting a shift in and it gets ridiculed a bit, but without it you get nothing for me.
"We've shown all those qualities tonight and we got blocks in and headers out and they were better, they played better than us but they couldn't score."
McCarthy rang the changes at half-time, sending on forwards Varney and Tom Lawrence, and the move paid dividends with the former scoring the winner eight minutes after being introduced.
The Ipswich boss added: "We didn't have it in the first half, that's why I made the subs, I wanted to stop them coming forward onto us as much as they were.
"I was tempted in the first half but I don't like doing that to players because it's detrimental to them. That's why I was screaming for the last five minutes to make sure we didn't concede and I could make changes."
Varney was one of them and McCarthy added: "He's got a contract to January. I knew a few clubs were sniffing so I went in because I knew I could trust him and he would fit in. I'm delighted for him because he's such a great guy around the place."
Derby manager Nigel Pearson felt defeat was tough on his side, which came just days after they were beaten 2-0 at home by Newcastle.
He said: "Mick said to me before the game he felt they'd been mugged on Friday and I think they've probably done that to us tonight.
"Of course it's a disappointing night and it's difficult to sell the idea that's okay when you are losing games and to score one goal in the league is a poor return, but I thought the players deserved to win the game.
"I thought they played exceptionally well. I felt for the fans and the players but the good thing tonight was I think the fans could see what the players are about and they stuck with them.
"In the context of what's happened so far this season, that was a very good performance which didn't get the result we were looking for. That was what I'm looking for - plus goals. Clearly we need to score and we need to score first."
Source: PA-WIRE
